LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 


Class 


WATER 


AND 


WATER    SUPPLIES 


BY 

JOHN     C.    THRESH 
1 1 

D.SC.  (LONDON);  M.D.  (VICTORIA);  D.P.H.  (CAMBRIDGE); 

HONORARY  DIPLOMATS  IN  PUBLIC  HEALTH,  ROYAL  COLLEGES  OF  PHYSICIANS  AND 

SURGEONS,  IRELAND.     MEDICAL  OFFICER  OF  HEALTH  TO  THE  ESSEX  COUNTY 

COUNCIL.     LECTURER  ON  "  PUBLIC  HEALTH,"  LONDON  HOSPITAL  MEDICAL 

COLLEGE.    FELLOW  OF  THE  INSTITUTE  OF  CHEMISTRY.     MEMBER  OF 

THE     SOCIETY     OF     PUBLIC    ANALYSTS.         ASSOCIATE     MEMBER     OF 

THE     BRITISH     ASSOCIATION     OF     WATERWORKS     ENGINEERS. 

EXAMINER     IN     HYGIENE,     LONDON     UNIVERSITY,     ETC. 

THIRD  EDITION,  REVISED   AND  ENLARGED 


UNIVERSITY 

OF 


PHILADELPHIA 
P.   BLAKISTON'S   SON   &   CO. 

1012   WALNUT   STREET 

1901 


Printed  In 


All  rights  reserved 


PREFACE 

(TO   THE   THIRD   EDITION). 

A  THIRD  edition  of  this  work  being  called  for,  the 
publishers  have  kindly  afforded  me  the  opportunity  of 
bringing  it  up  to  date,  and  of  including  additional 
chapters  on  the  Protection  of  Water  Supplies. 

I  have  to  thank  many  Medical  Officers  of  Health  and 
Waterworks  Engineers  for  the  verification  of  statements 
and  for  information  furnished. 

The  legal  portion  has  been  revised  by  my  friend,  Mr. 
John  C.  Freeman,  Clerk  to  the  Maldon  Rural  District 
Council,  and  my  thanks  are  due  to  him  for  his  valuable 
assistance. 

I  have  also  to  thank  my  assistant,  A.  E.  Porter,  M.D., 
D.P.H.,  and  my  late  assistant,  R.  W.  C.  Pierce,  M.B., 
D.P.H.,  now  Medical  Officer  of  Health  for  the  Guildford 
District,  for  revising  the  proofs  and  assisting  me  generally 
in  preparing  this  edition  for  the  press. 


JOHN  C.  THRESH. 


Ill  TEMPLE  CHAMBERS, 

LONDON,  E.G.,  May,  1901. 


161911 


PREFACE 

(TO   THE   FIRST   AND   SECOND   EDITIONS). 

IT  is  now  fully  recognised  that  an  abundant  supply  of 
pure  water  is  an  absolute  necessity  for  the  preservation 
of  health,  and  that  one  of  the  chief  duties  of  all  Sanitary 
Authorities  is  to  see  that  all  the  inhabitants  of  their 
districts  have,  within  a  reasonable  distance,  an  available 
supply  of  wholesome  water  wherever  such  can  be  obtained 
at  a  reasonable  cost. 

The  main  object  of  this  little  work  is  to  place  within 
the  reach  of  all  persons  interested  in  public  health  the 
information  requisite  for  forming  an  opinion  as  to  whether 
any  supply  or  proposed  supply  is  sufficiently  wholesome 
and  abundant,  and  whether  the  cost  can  be  considered 
reasonable. 

It  does  not  pretend  to  be  a  treatise  on  Engineering, 
yet  it  is  hoped  that  it  contains  sufficient  detail  to  enable 
any  one  who  has  studied  it  to  consider  intelligently 
any  scheme  which  may  be  submitted  for  supplying  a 
community  with  water,  whether  that  community  be  large 
or  small. 

Whilst  all  our  large  towns  have  obtained  more  or  less 
satisfactory  supplies  of  water  for  their  inhabitants,  the 
great  bulk  of  the  population  living  in  villages  and  rural 
districts  generally  is  still  dependent  upon  improperly 


vi  WATER  SUPPLIES 

constructed  and  unprotected  shallow  wells,  or  even  upon 
more  questionable  sources  for  its  supply.  The  cause  is 
not  far  to  seek.  Neither  the  Sanitary  Authorities  nor 
the  rural  populations  are  as  yet  fully  alive  to  the  im- 
portance of  a  good  water  supply,  and  have  no  knowledge 
of  how  to  set  about  remedying  the  present  conditions 
even  if  regarded  as  unsatisfactory.  There  is  also  a 
widespread  and  generally  erroneous  impression  that 
scattered  populations  cannot  be  supplied  with  water 
from  sources  at  a  distance  at  a  reasonable  cost.  To 
prove  the  fallacy  of  this  impression  particulars  are  given 
of  a  few  typical  schemes  which  have  been  successfully 
carried  out  in  thinly-populated  districts,  and  it  is  hoped 
that  the  example  set  by  these  enterprising  authorities 
will  be  widely  followed. 

The  supply  of  water  to  rural  districts  is  a  question 
which  has  engrossed  the  attention  of  Medical  Officers  of 
Health  ever  since  such  officials  were  appointed,  but  too 
often  they  have  been  satisfied  with  merely  reporting  that 
water  supplies  were  unsatisfactory.  Such  reports  are  not 
sufficient  to  overcome  the  apathy  of  Sanitary  Authorities 
or  to  arouse  any  great  interest  in  the  subject  in  the 
districts  concerned.  The  Medical  Officer  must  not  only 
prove  that  the  present  supplies  are  inadequate  in  quantity 
or  unwholesome  in  quality,  or  both,  but  in  conjunction 
with  the  Surveyor  he  must  be  prepared  to  formulate  a 
scheme  and  to  prove  that  it  is  practicable.  To  enable 
him  to  do  this  is  one  of  the  objects  of  this  work.  The 
practical  experience  gained  in  large  rural  districts  in 
which  it  has  been  my  privilege  to  submit  such  schemes 
and  see  them  carried  to  a  successful  completion,  is 
embodied  in  various  chapters,  and  I  hope  will  prove  of 


PREFACE  vii 

value  to  all  who  are  interested  in  the  well-being  of  our 
rural  populations. 

A  brief  resumd  of  the  law  relating  to  water  supplies 
is  given  in  the  final  chapter,  and  I  have  to  thank  my 
friend,  A.  Freeman,  Esq.,  Clerk  to  the  Maldon  Rural 
District  Council,  for  many  suggestions,  and  for  revising 
everything  therein  relating  to  the  law. 

All  schemes  for  establishing  public  water  supplies  in 
districts  hitherto  dependent  upon  water  from  questionable 
sources  are  certain  to  meet  with  considerable  opposition, 
but  District  Councils  and  their  officers  may  take  heart 
from  the  experience  of  others.  Carry  out  the  work 
satisfactorily,  and  those  who  were  loudest  in  opposition 
will  ere  long  frankly  acknowledge  the  value  of  the  boon 
conferred. 

JOHN  C.  THRESH. 

CHELMSFORD,  January,  1896. 


CONTENTS. 

CHAPTEK  I. 

WATER,    ITS    COMPOSITION,    PROPERTIES,    ETC. 

Composition  of  water — Pure  water  not  found  in  nature — Effect  of 
temperature — Maximum  density — Latent  heat — Expansion  during 
act  of  freezing — Boiling  point  influenced  by  atmospheric  pressure 
— Evaporation  of  water,  snow  and  ice — Solvent  powers — Common 
constituents  of  natural  waters — Hardness — Action  on  metals — Lead 
poisoning — Hygienically  pure  water — Mineral  waters — Potable 
waters,  classification  of Pages  1-13 

CHAPTER  II. 

RAIN    AND   RAIN   WATER. 

Distillation — Moisture  contained  in  the  atmosphere — Evaporation 
from  the  ocean,  from  land  surfaces,  etc. — The  causes  of  rain — 
Rainfall,  by  what  influenced,  how  determined — Constituents  of 
rain  water,  effect  of  proximity  to  ocean,  towns,  etc. — Pollution 
during  collection  and  storage — Amount  available  from  roofs  and 
specially  prepared  surfaces — Bain-water  separators — Storage  for 
domestic  purposes — Rainfall  source  of  all  water  supplies — Natural 
waters  in  order  of  purity— Composition  of  rain  water  Pages  14-30 

CHAPTER  III. 

SURFACE     WATER. 

Characteristics  of,  from  various  geological  formations — Effect  of  soil  and 
cultivation  of  ground  surface — Ponds,  lakes  and  reservoirs — Lakes 
as  natural  reservoirs,  Loch  Katrine,  Lake  Vyrnwy,  Thirlmere— 
Aberystwith  water  supply — Glasgow  water  supply — Analyses  of 
upland  surface  waters — Analyses  of  public  water  supplies  derived 
from  uplands  and  moorlands Pages  31-44 


X  WATER  SUPPLIES 

CHAPTER  IV. 

SUBSOIL     WATER. 

Bogs,  marshes  and  swamps — Pervious  and  non-pervious  subsoils — 
"Pockets"  of  gravel — Permeability,  imbibition  and  saturation  of 
rock — Variation  in  level  of  subsoil  water  and  the  causes  thereof — 
Amount  of  water  held  by  various  rocks — Movement  of  subsoil 
water — Proportion  of  rainfall  which  percolates  into  subsoil — 
Water,  how  obtainable  from  subsoil — Quantity  obtainable,  how 
ascertained  —  Shallow-well  water  —  Subterranean  rivers  —  Buda 
Pesth  and  Perth  examples  of  towns  supplied  from  subsoil — Quality 
of  subsoil  water — How  polluted— Koch  on  "  subsoil  water  " — Towns 
in  Massachusetts  supplied  with  subsoil  water — Effect  of  towns, 
villages,  etc.,  on  subsoil  water— Example,  village  of  Writtle, 
Essex — Analyses  of  shallow-well  waters  from  various  geological 
sources — Analyses  of  public  and  other  supplies  derived  from 
subsoil Pages  45-58 


CHAPTER  V. 

NATURAL    SPRING  WATERS. 

Perennial,  intermittent  and  variable  springs — Origin  of  springs — Cold, 
hot,  ascending  and  descending  springs — Artificial  springs — The 
natural  springs  of  Clifton,  Bath,  Buxton,  Matlock  and  Chelten- 
ham— Springs,  how  gauged — Causes  of  variation  in  flow — Dr. 
Whitaker  on  the  King's  Lynn  water  supply — Bristol  supplied 
from  springs — Utilisation  of  springs — Character  of  spring  water 
from  various  geological  sources — Analyses  of  spring  waters 

Pages  59-73 


CHAPTER  VI. 

DEEP-WELL   WATERS. 

Difference  between  "shallow"  and  "deep"  wells — Artesian  wells — 
Subterranean  reservoirs  or  rivers — Source  of  deep-well  water — 
Chief  water-bearing  strata — Supply  obtainable  from  deep  wells, 
how  affected  :  by  extent  and  character  of  outcrop,  average  rainfall, 
continuity  of  water-bearing  strata,  selection  of  site — Advantage's 
of  underground  water  supplies — Effect  of  proximity  to  other  wells 
— Supply  to  Long  Eaton,  Castle  Donington  and  Melbourne — 
Supply  of  deep-well  water  for  the  City  of  London — Report  of 
Royal  Commission  on  metropolitan  water  supply — Deep  wells  in 
the  Colonies,  United  States — Recent  Analyses  of  deep-well  waters 

Pages  74-89 


CONTENTS  xi 

CHAPTER  VII. 

RIVER   WATER. 

Catchment  basins — Drainage  areas—  Effects  of  towns,  villages,  manu- 
factories, etc.,  within  a  drainage  area-  Self -purification  of  rivers — 
The  Seine,  Thames,  Tees,  etc. — Flow  of  streams — Amount  of 
water  available,  factors  influencing — Maximum,  minimum  and 
mean  rainfall— Seasonal  variation  of  rainfall,  effects  of — Portion 
of  rainfall  reaching  rivers — Stream  gaugings,  different  methods 
of — Towns  deriving  their  water  supplies  from  rivers 

Pages  90-108 


CHAPTER  VIII. 

QUALITY   OF   DRINKING   WATERS. 

Colour  of  pure  and  impure  waters — Taste  and  odour,  by  what  in- 
fluenced— Organisms  found  in  water — Pathogenic  and  other 
bacteria  affecting  odour  or  taste—Effect  of  mineral,  animal 
and  vegetable  impurities—  Turbidity,  to  what  due — Soluble  con- 
stituents of  potable  waters,  inorganic  and  organic — Typical 
analyses — What  constitutes  a  good  potable  water 

Pages  109-132 


CHAPTER  IX. 

IMPURE    WATER   AND    ITS    EFFECT    UPON    HEALTH. 

Constituents  which  may  cause  diarrhoea — Diseases  caused  by  mineral 
constituents :  goitre,  diarrhoea,  plumbism,  etc. — Diseases  due  to 
specific  organisms :  malaria,  enteric  or  typhoid  fever,  cholera, 
yellow  fever,  oriental  boils,  .Zoo-parasitic  diseases :  Bilharzia 
hcematobia,  Filaria  sanguinis,  Filaria  dracunculus,  etc. — Diseases 
of  animals  caused  by  impure  water  ....  Pages  133-177 


CHAPTER  X. 

THE    INTERPRETATION   OF    WATER   ANALYSES. 

The  inorganic,  organic  and  bacterial  constituents,  relative  importance 
of — Erroneous  conclusions  may  be  drawn  from  both  chemical  and 
bacteriological  analyses — Significance  of  chlorides,  nitrates  and 
nitrites,  ammonia,  phosphates,  organic  matter  —  Albumenoid 
ammonia — Organic  carbon  and  oxygen— Oxygen  absorbed — Sir 
Charles  Cameron  on  the  value  of  chemical  analyses — Intermittent 
pollution— Variation  in  quality  of  water  from  one  and  the  same 
source — Table  of  analyses,  showing  how  little  dependence  can  be 


WATER  SUPPLIES 

placed  upon  the  results  of  a  chemical  analyses — :Remarks  on  the 
waters  referred  to  in  the  Table  of  Analyses — The  bacteriological 
examination  of  water — Microbes  found  in  water  and  their  signifi- 
cance— Standard  of  purity,  absurdity  of — Importance  of  the 
examination  of  the  source  of  the  water  .  .  Pages  178-217 


CHAPTER  XI. 

THE    POLLUTION   OF   DRINKING   WATER. 

Pollution  at  its  source — Surface  and  river  waters — Subsoil  water — Deep- 
well  water — Pollution  arising  during  storage— Pollution  during 
distribution Pages  218-241 

CHAPTER  XII. 

THE    SELF-PURIFICATION   OF   RIVERS. 

Rivers,  how  polluted — Natural  purification — Oxidation,  sedimentation, 
effect  of  sunlight,  organisms,  etc. — Can  a  sewage-polluted  river 
water  ever  be  rendered  perfectly  safe  for  a  public  water  supply  ? 

Pages  242-252 

CHAPTER  XIII. 

THE   PURIFICATION   OF   WATER   ON   THE    LARGE   SCALE. 

Sedimentation — Filtration,  efficiency  of,  how  determined — Prof.  P. 
Frankland's  experiments  at  the  London  Waterworks — Table 
showing  effect  of  subsidence — Experiments  conducted  by  the 
Massachusetts  State  Board  of  Health — Effects  of  (a)  rapidity  of 
filtration,  (b)  thickness  of  filtering  media,  (c)  fineness  of  filtering 
media,  (d)  scraping  the  surface  of  filter,  etc. — Conclusions  based 
upon  Massachusetts  experiments — Dr.  Koch  on  the  "  conditions 
necessary  for  efficient  filtration " — The  Altona  Waterworks — 
Action  of  sand — Construction  of  filter  beds — Size  and  number  of 
beds  'required — Table  showing  area  of  filter  and  rate  of  filtration 
at  different  works — Natural  filtration — Filter  galleries — Atkins'x 
scrubbers — American  filtering  machines — Polarite,  spongy  iron, 
magnetic  carbide  and  other  filtering  materials ;  where  used ; 
efficiency  of — Sand  washing — "Softening  "  purifies  water 

Pages  253-277 

CHAPTER  XIV. 

DOMESTIC   PURIFICATION. 

Low.- pressure  filters — High  -  pressure  filters — Table  filters — Cottage 
filter — Efficiency  of  filters — Distillation — Aeration — Purification 
by  the  addition  of  chemicals  ....  Pages  278-287 


CONTENTS  xiii 

CHAPTER  XV. 

THE   SOFTENING   OF   HARD   WATER. 

Softening  by  boiling ;  by  addition  of  chemicals — Clark's  lime  process — 
Colne  Valley  Waterworks — Atkins'  process — Southampton  Water- 
works—The "Porter-Clark"  process — The  Stanhope  water  softener 
—The  Howatson  "  Softener  " — Stroud  Waterworks — Cost  of  various 
processes — Saving  effected  by  using  soft  water  in  houses,  institu- 
tions and  towns Pages  288-304 

CHAPTER  XVI. 

QUANTITY   OF   WATER   REQUIRED    FOR   DOMESTIC    AND 
OTHER   PURPOSES. 

Variation  in  rural  and  urban  districts — Purposes  for  which  water  is 
required — Various  estimates  of  amount  required  for  different 
purposes— Constant  versus  intermittent  supplies — Tables  showing 
amount  supplied  in  various  towns — Newcastle  and  Wolverhampton 
records — Daily  supply  by  London  Water  Companies — Waste  of 
water— Unnecessary  consumption — Prevention  of  waste — Saving 
effected  by  Deacon's  meters  at  Liverpool,  Exeter  and  elsewhere — 
Amount  of  water  required  in  tropical  climates — Daily  quantity 
required  by  various  animals Pages  305-318 


CHAPTER  XVII. 

SELECTION   OF   SOURCES   OF   WATER   SUPPLY   AND   AMOUNT 
AVAILABLE    FROM    DIFFERENT    SOURCES. 

Various  sources — Finding  water — Water  "finders" — Selection  of  site 
for  wells — Drainage  area — The  Stockport  water  supply — Amount 
yielded  by  various  water-bearing  formations  .  Pages  319-341 


CHAPTER  XVIII. 

THE    PROTECTION   OF    UNDERGROUND   WATER   SUPPLIES 

Nature  of  pervious  surface — Purifying  action  of  soil — Epidemics  due 
to  use  of  polluted  subsoil  water— Growth  of  typhoid  bacillus  in 
soil— Abba's  experiments  on  the  filtering  power  of  the  subsoil  at 
Turin — Subsoil  sterile  beyond  a  certain  depth — Bate  of  motion  of 
subsoil  water— Motion  affected  by  pumping— Protective  areas- 
Protection  of  tube-wells — Necessity  for  periodical  examination  of 
sources  of  water  supply Pages  342-357 


xiv  WATER  SUPPLIES 

CHAPTER  XIX. 

THE    PROTECTION    OF   SURFACE-WATER   SUPPLIES. 

Surface-water  supplies  rarely  responsible  for  outbreaks  of  disease — 
Necessity  for  control  of  gathering  ground — Difficulties  involved  in 
obtaining  control — Necessity  for  ample  storage— Desirability  of 
filtration — Vegetable  growths  in  reservoirs — The  Local  Govern- 
ment Board  circular  on  the  supervision  by  sanitary  authorities 
over  the  public  supplies  for  which  they  are  responsible 

Pages  358-363 

CHAPTER  XX. 

WELLS   AND   THEIR   CONSTRUCTION. 

Shallow  wells — How  usually  constructed — Improved  methods  of 
constructing — Tube  wells — Koch's  advice  with  reference  to  shallow 
wells  —  Abyssinian  tube  wells  —  Amount  of  water  yielded  by 
various  tube  wells — Cost  of  sinking  wells — Cost  of  driving  tubes — 
Deep  wells — Pumping  directly  from  tubes — Pumping  from  storage 
reservoir — Multiplication  of  tube  wells  to  increase  supply — Defects 
in  tube  wells — Yield  of  water  from  deep  wells — Deep  wells  in 
Queensland,  South  Australia,  Victoria,  Cape  of  Good  Hope, 
United  States  and  other  countries  .  .  .  Pages  364-391 


CHAPTER  XXI. 

PUMPS   AND   PUMPING   MACHINERY. 

Various  types  of  pump — Lifting  pumps — Plunger  or  force  pumps — 
Centrifugal  pumps — Bucket  and  Plunger  pump — Quantity  of  water 
delivered  by  each  stroke  of  pump — "Efficiency"  of  pumps — 
Height  to  which  water  can  be  raised,  (a)  by  manual  labour,  (b)  by 
donkey  working  a  gin,  (c)  by  horse  working  a  gin,  by  one  horse- 
power engine — Wind  engines — Water  as  a  motive  power — Rams, 
turbines  and  water-wheels — Fuel  engines — Hot-air  engines — Oil 
engines — Gas  engines — Steam  engines — Horse-power  required 

Pages  392-418 

CHAPTER  XXII. 

THE   STORAGE   OF   WATER. 

Impounding  reservoirs — Settling  reservoirs — Service  reservoirs — Classi- 
fication of  water-works — Effect  of  Storage — Covered  versus  open 
reservoirs — Capacity  of  storage  reservoirs  to  compensate  for  the 
inequality  of  hourly  consumption  and  provide  reserve  in  case  of 
fire — Rain-water  tanks — House  cisterns  .  .  .  Pages  419-433 


CONTENTS  xv 

CHAPTER  XXIII. 

THE    DISTRIBUTION   OF   WATER. 

The  "constant"  system — The  "intermittent"  system — Conduits  and 
aqueducts,  size  of,  fall  required — Various  kinds  of  mains — Eytel- 
wein's  formula — Depth  of  mains — Dead  ends,  advantages  and 
disadvantages — House  service  pipes,  lead,  tin-lined  lead,  wrought 
iron,  galvanised  iron — Regulations  made  under  the  Metropolis 
Water  Act,  1871 Pages  434-446 

CHAPTER  XXIV. 

THE    LAW   RELATING   TO   WATER   SUPPLIES. 

Land  and  Water  rights,  voluntary  and  compulsory  purchase  of — Sale 
of  rights  by  limited  owners — Roadside  waste  land,  ownership 
of — Precautions  to  be  taken  when  purchasing  lands,  springs, 
etc. — Rights  of  riparian  proprietors — Water  flowing  in  definite 
channels — Underground  water — Waterwork  Clauses  Acts — Water 
rates  and  rents — Cost  and  maintenance  of  waterworks,  by  whom 
borne — Parish  Councils  and  water  supplies — The  Public  Health 
Act,  1875— The  Public  Health  (Water)  Act,  1875— The  Limited 
Owners  Reservoirs  and  Water  Supply  Further  Facilities  Act,  1877 
— Important  legal  decisions  affecting  water  supplies 

Pages  447-468 

CHAPTER  XXV. 

RURAL   AND  VILLAGE   WATER  SUPPLIES. 

General  neglect  to  provide  rural  supplies,  causes  of— Advantages  of 
public  supplies — Description  of  typical  works,  with  cost  of  works, 
cost  of  maintenance,  water  rates  levied,  etc. — Spring  water  raised 
by  hydraulic  ram — Gravitation  works — Spring  water  raised  by 
steam  pump — Subsoil  water  raised  by  steam  pump — Subsoil  water 
gravitation  works — Spring  water  raised  by  water-wheel — Deep-, 
well  water  raised  by  windmill — Spring  water  pumped  by  turbine 
— Deep-well  water  raised  by  an  oil  engine — Spring  water  raised 
by  a  gas  engine — Table  of  rates — Charges  for  domestic  supply  of 
water  in  various  towns Pages  469-483 

CHAPTER  XXVI. 

WATER   CHARGES. 

Water  rates,  basis  of — Domestic  purposes — Supply  by  meter — Water 
charges  in  various  districts Pages  484-497 

GENERAL  INDEX Pages  499-517 

INDEX  OF  PROPER  NAMES      ....,,    Pages  519-527 


OF  THE 

UNIVERSITY 

OF 


WATER    SUPPLIES. 

CHAPTER    I. 

WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC. 

FROM  the  time  of  Aristotle  until  the  close  of  the  eighteenth 
century,  water  was  regarded  as  an  elementary  substance, — 
that  is,  one  which  could  not  be  split  up  or  decomposed  into 
any  simpler  forms  of  matter.  In  1781  an  English  chemist, 
Henry  Cavendish,  discovered  that  when  two  gases,  oxygen 
and  hydrogen,  were  mixed  together  in  certain  proportions 
(two  of  hydrogen  to  one  of  oxygen)  and  an  electric  spark 
passed  through  the  mixture,  combination  took  place  and 
water  was  formed.  Many  other  ways  have  since  been 
devised  for  causing  these  gases  to  combine  and  for  demon- 
strating that  water  is  the  product  formed.  By  other 
methods  also  water  can  be  decomposed  and  made  to  yield 
the  two  elements  which  alone  enter  into  its  composition 
when  pure.  For  example,  if  a  strong  current  of  electricity  be 
passed  through  water,  bubbles  of  gas  are  given  off  from  each 
terminal  or  pole.  At  the  one  pole  the  gas  consists  of  pure 
oxygen,  at  the  other  of  pure  hydrogen,  and  the  volumes 
obtained  are  two  of  the  latter  to  one  of  the  former.  Aa 
oxygen  is  sixteen  times  as  heavy  as  hydrogen,  the  composi- 
tion of  pure  water  is  as  under :  — 

By  Volume.  By  Weight. 

Oxygen        ...         1  part        .        .        8  parts. 
Hydrogen    ...        2  parts      .         .         1  part. 


2  WATER  SUPPLIES 

Pure  water  is  a  chemical  curiosity.  The  moisture  which 
bedews  the  tube  in  which  the  mixture  of  hydrogen  and 
oxygen  has  been  exploded  is  water  in  its  purest  form.  If, 
however,  it  be  exposed  to  the  air  or  be  allowed  to  stand  in 
contact  with  any  substance  (save  perhaps  some  of  the  less 
oxidisable  metals,  as  platinum  and  gold)  it  will  absorb 
gases  from  the  air  or  dissolve  some  of  the  material  of  the 
vessel  in  which  it  is  placed,  and  from  a  chemical  point  of 
view  is  no  longer  pure.  Pure  water  does  not  occur  in  nature, 
even  rain  water  caught  in  mountainous  districts  far  from  the 
smoke  of  towns  or  the  haunts  of  men  contains  traces  of 
impurities  taken  up  from  the  air.  When  the  foreign  sub- 
stances are  present  in  sd  small  quantities  as  not  appreciably 
to  affect  the  physical  properties  of  the  water,  or  to  render  it 
unfit  for  domestic  and  manufacturing  purposes,  it  is  popu- 
larly spoken  of  as  "  pure,"  and  it  is  in  this  sense  that  the 
term  "  pure  water  "  will  in  future  be  used  throughout  this 
book. 

Pure  water,  when  viewed  in  small  quantities,  appears  to  be 
perfectly  colourless,  but  when  viewed  in  bulk,  as  in  the  white 
tiled  baths  at  Buxton,  and  in  certain  Swiss  lakes,  it  is  seen  to 
possess  a  beautiful  greenish-blue  tint.  A  very  small  amount 
of  suspended  or  dissolved  impurity  is  sufficient  to  obscure 
this  colour.  Impure  waters  almost  invariably  exhibit  a 
colour  varying  from  green  to  yellow  and  brown  when 
examined  in  suitable  tubes  about  two  feet  in  length,  but,  as 
will  be  seen  later,  it  does  not  always  follow  that  a  water  with 
a  brownish  tint  is  too  impure  for  domestic  use.  Pure  water 
is  absolutely  devoid  of  odour  and  is  destitute  of  taste.  The 
purest  is  insipid,  but  if  such  a  water  be  aerated  by  agitation 
with  air  or  by  filtration  through  a  porous,  air-containing 
medium,  the  insipidity  disappears.  Practically,  water  is 
incompressible,  but  the  volume  of  a  given  weight  varies  very 
considerably  with  the  temperature.  With  very  few  excep- 
tions all  fluids  expand  when  heated  and  contract  when 
cooled.  The  most  important  exception  is  water  between 


WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC.          3 

certain     temperatures.      As     the     effect     of     heat     upon 
water    has    a    direct    bearing    upon    certain    points    con- 
nected    with     water     supplies,     it     is     necessary     briefly 
to     consider     the     action     of     change     of     temperature. 
If    a    quantity    of    pounded     ice,     with     a    little     water, 
be  placed   in   a  glass  beaker   in  which   two  thermometers 
are  placed,  one  at  the  bottom  and  the  other  near  the   surface 
of  the  mixture,  it  will  be  found  that  both  indicate  the  same 
temperature,  0°  C.     If  now  some  source  of  heat  be  applied 
to  the   beaker,   it  will   be   observed   that   neither   thermo- 
meter   will    indicate     any    increase    of    temperature    until 
the  last  particle  of  ice  is  melted.     The  heat,  as  such,  has 
disappeared,  its  effect  upon  the  ice  being  not  to  raise  its 
temperature  but  to  liquefy  it.     The  same  fact  can  be  proved 
by    another  simple  experiment,  which    enables  us  also  ,to 
measure  the  amount  of  heat  which  disappears  or  becomes 
latent.     If  one  pint  of  water,   at  the  temperature   of  0° 
C.,    be    mixed    with    one    pint    of    water    at    79°    C.,    the 
temperature  of  the  mixture  will  be  the  mean,  39.5°  C.     If, 
however,  ice  at  0°  C.  be  substituted  for  the  cold  water, 
the   whole   of   the   ice   will   melt,  but   the   temperature   of 
the  resulting  fluid  will  not  be  39.5°   C.   but   0°.  ^  Water 
at   0°,   i.e.   at   its  freezing   point,   may   be  said   to   be  ice 
plus  heat.     This   heat,   which   becomes   latent   during   the 
process  of  liquefaction,  is  again  given  off  when  water  freezes. 
As  the  surface  of  a  sheet  of  w^ter  freezes,  the  water,  in  the 
act  of  solidification,  gives  up  a  certain  amount  of  heat.   This 
raises  the  temperature  of  the  remaining  water,  and  so  the 
process  of  freezing  or  solidification  is  retarded.     Were  not 
this  the  case,  during  winter  water  would  freeze  with  great 
rapidity,  and  the  ice  so  formed  would  as  rapidly  melt  when 
the  weather  became  warmer.     Such  a  condition  of  things 
would  render  all  but  the    tropical  and  sub-tropical  regions 
practically  uninhabitable  during  certain  portions  of  the  year. 
As  soon  as  the  temperature  sank  below  zero,  ice  would  so 
quickly   form  that  our  lakes,  reservoirs,  streams,  etc.,   would 


4  WATER  SUPPLIES 

contain  only  solid  ice.  Snows  would  melt  so  rapidly  with 
a  slight  increase  of  temperature  that  most  disastrous  floods 
would  follow.  This  sudden  freezing  also  would  result  in  the 
bursting  of  every  water  main  and  pipe,  since  water  in  the 
act  of  solidification  expands  considerably,  eleven  pints  of 
water  when  frozen  forming  twelve  pints  of  ice,  or,  in  other 
words,  water  expands  one-eleventh  of  its  volume  in  the  act  of 
freezing.  The  effects  of  this  expansion  are  disastrous  enough 
to  water  mains  and  pipes  when  the  freezing  process  is 
retarded  by  the  heat  given  off  by  the  water  as  it  solidifies ; 
but  if  the  solidification  took  place  suddenly,  as  soon  as  the 
temperature  fell  -slightly  below  zero,  the  expansion,  being 
uniform  in  every  direction,  would  burst  every  pipe  or  vessel 
in  which  the  water  was  contained.  The  force  so  exerted  in 
the  act  of  freezing  is  enormous.  Thick  iron  shells  filled 
with  water  and  securely  plugged  are  easily  burst  by  exposure 
to  the  cold  of  a  Canadian  winter's  night. 

Water  is  at  its  maximum  density  at  4°  C.  If  cooled 
below  that  temperature  it  expands;  if  the  temperature  is 
raised  it  also  expands.  It  thus  differs  from  nearly  all  other 
liquids,  which  at  all  temperatures  between  their  freezing 
and  boiling  points  expand  when  heated  and  contract  when 
cooled.  If  a  jar  of  water  be  exposed  to  a  temperature  below 
zero,  and  two  thermometers  are  placed  in  the  water,  one  at 
the  bottom  and  the  other  near  the  surface,  it  will  be  found 
that  the  thermometer  at  the  bottom  records  a  continuously 
lower  temperature  than  the  one  near  the  surface  until 
4°  C.  is  reached.  Up  to  this  point  the  colder  water,  being 
heavier,  has  continued  to  fall  to  the  bottom  of  the  jar. 
Below  this  temperature  the  upper  instrument  will  record  the 
lower  temperature,  proving  that  at  temperatures  below  4° 
water  becomes  specifically  lighter.  If  such  were  not  the 
case  the  water  at  the  bottom  of  the  vessel  would  con- 
tinue the  colder  and  would  be  the  first  to  freeze.  Solidifica- 
tion would  take  place  from  below  upwards.  The  result 
would  be  that  during  a  severe  winter  our  streams  and  lakes 


WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC.          5 

would  become  one  mass  of  ice,  which  all  the  heat  of  the 
ensuing  summer  would  be  unable  to  melt.  To  quote 
Professor  Roscoe,  "  If  it  were  not  for  this  apparently 
unimportant  property  our  climate  would  be  perfectly  arctic, 
and  Europe  would  in  all  probability  be  as  uninhabitable  as 
Melville  Island."  As  it  is,  in  large  lakes  and  rivers  the 
temperature  of  the  deep  water  never  falls  below  4° 
during  the  winter,  and  the  surface  water  when  cooled  to 
zero  begins  to  freeze,  and  at  the  same  time  to  liberate  its 
latent  heat,  which  raises  the  temperature  of  the  layer 
beneath,  and  so  retards  the  cooling  process.  That  the 
habitability  of  such  a  large  portion  of  the  globe  should 
depend  upon  these  exceptional  properties  is  a  remarkable 
fact. 

At  the  sea-level  mean  barometric  pressure  (760  mm.) 
water  boils  at  100°  C.  When  the  atmospheric  pressure 
is  decreased,  as  in  ascending  a  mountain,  or  when  the  water- 
containing  vessel  is  placed  under  the  receiver  of  an  air  pump 
and  a  portion  of  the  air  exhausted,  the  boiling  point  is 
lowered.  On  the  summits  of  the  highest  mountains  water 
boils  at  so  low  a  temperature  that  meat  cannot  be  thoroughly 
cooked  in  it,  and  in  the  vacuum  produced  by  a  properly- 
constructed  air  pump  water  can  be  made  to  boil  rapidly  at 
ordinary  temperatures,  and  as  during  evaporation  heat  is 
lost,  the  temperature  is  reduced  so  low  that  the  water 
freezes  as  it  boils.  If  boiled  in  an  open  vessel  water  rapidly 
and  visibly  evaporates,  but  this  evaporation  takes  place  in- 
visibly at  all  temperatures,  the  more  slowly  the  lower  the 
temperature.  Even  snow  and  ice  slowly  disappear  by 
evaporation  during  winter.  The  rate  of  evaporation  from 
an  exposed  surface  depends  upon  several  factors,  the  more 
important  being  the  temperature,  the  velocity  of  the  air 
in  contact  with  the  surface,  and  the  dryness  of  the  air.  On 
a  dry,  hot,  windy  day,  evaporation  is  rapid ;  on  a  damp, 
cold,  calm  day  evaporation  approaches  its  minimum.  The 
bearing  of  these  facts  upon  the  subject  of  rainfall  and  the 
Storage  of  water  will  be  discussed  in  subsequent  chapters, 


6  WATER  SUPPLIES 

Water  has  remarkable  solvent  powers.  The  number  and 
variety  of  substances  which  it  can  take  into  solution  greatly 
exceed  that  of  any  other  fluid.  Some  substances,  such  as 
sugar  and  salt,  it  dissolves  in  large  quantities  and  with  con- 
siderable rapidity ;  others,  such  as  the  constituents  of  most 
rocks,  it  only  dissolves  in  small  quantity  and  very  slowly. 
Many  gases,  such  as  ammonia  and  hydrochloric  acid,  it 
absorbs  with  avidity,  taking  up  many  times  its  own  volume ; 
others,  such  as  nitrogen  and  oxygen,  the  two  principal 
constituents  of  the  atmosphere,  it  only  dissolves  in  small 
proportions  ;  whilst  of  others,  such  as  carbonic  acid,  it  can 
dissolve  about  its  own  volume.  This  property  of  absorbing 
or  dissolving  gases  is  a  most  important  one.  It  explains 
how  water  may  become  contaminated  by  mere  exposure  to 
an  impure  atmosphere,  as  when  an  uncovered  cistern  is 
placed  in  a  water-closet,  or  when  an  overflow  pipe  is  directly 
connected  with  a  drain.  One  of  the  most  important  con- 
stituents of  nearly  all  natural  waters  is  carbonic  acid  gas. 
This  gas  is  always  present  in  the  air,  and  all  rain  waters 
contain  some  of  it,  but  still  more  is  taken  up  by  the  water 
as  it  percolates  through  ground  covered  with  vegetation. 
The  presence  of  this  gas  increases  the  solvent  powers  of  the 
water,  enabling  it  to  dissolve  carbonate  of  lime  (chalk  and 
limestone)  and  carbonate  of  magnesia  very  freely.  If  a 
sample  of  tolerably  "  hard  "  water  be  placed  in  a  flask  and 
gently  heated,  bubbles  of  gas  will  be  observed  to  form  in 
the  water,  rise  to  the  surface  and  burst.  These  bubbles  are 
the  gases  (oxygen,  nitrogen,  and  carbonic  acid)  which  were 
previously  held  in  solution  by  the  water.  The  carbonic  acid, 
being  most  soluble,  is  not  wholly  given  off  until  the  water 
boils.  As  this  gas  is  removed  the  water  will  become  more 
or  less  turbid  from  the  deposition  of  minute  solid  particles 
of  carbonate  of  lime  or  of  this  substance  with  carbonate  of 
magnesia.  One  gallon  of  pure  water  will  only  dissolve  from 
two  to  three  grains  of  these  carbonates,  but  when  the  water 
contains  carbonic  acid  it  may  dissolve  twenty  or  more 


WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC.          7 

grains.  The  whole  of  this  excess  is  thrown  out  of  solution 
if  the  water  be  boiled  so  as  to  expel  the  acid.  If  the  water 
now  be  filtered  or  decanted  from  the  deposited  solid  matter, 
and  again  boiled  until  the  whole  has  evaporated,  a  greyish- 
white  residue  will  be  found  on  the  bottom  of  the  vessel. 
This  consists  of  the  mineral  (and  possibly  some  organic) 
substances  which  the  water  had  held  in  solution.  The 
amount  will  vary  with  the  character  of  the  water.  Rain 
water  leaves  a  very  slight  residue,  whilst  that  yielded  by  sea 
water  is  very  abundant  indeed.  If  this  residue  be  free  from 
organic  matter  (usually  derived  from  decaying  animal  or 
vegetable  substances),  it  will  undergo  little  or  no  change 
in  colour  when  heated  to  redness;  whereas,  if  organic 
impurity  be  present,  it  will  char  when  heated,  the  residue 
becoming  brown  or  even  black. 

The  common  constituents  of  natural  waters  may  be  classi- 
fied as  follows  :  — 

GASEOUS.  Carbonic  acid,  oxygen,  and  nitrogen. 

SOLIDS,     (a)  Mineral.  Carbonates  of  lime  and  magnesia. 

Sulphates  of  lime,  magnesia,  and  soda. 
Chloride  of  sodium  (common  salt). 

(b)  Organic.  Products  of  decomposition  of  animal  and  vege- 
table matter. 

Besides  the  matters  in  solution  many  waters  contain  others 
in  suspension,  and  these  again  may  be  divided  into  inorganic 
(mineral),  such  as  clay,  fine  sand,  debris  of  rocks,  etc.,  and 
organic,  such  as  the  lower  forms  of  animal  and  vegetable  life, 
living  or  dead.  The  nature  of  the  mineral  constituents  will 
be  more  fully  discussed  in  the  chapters  relating  to  waters 
from  different  sources,  and  the  organic  impurities  in  the 
section  devoted  to  the  quality  of  waters. 

Waters  containing  very  small  quantities  of  lime  and 
magnesia  salts  are  called  "  soft,"  since  they  lather  freely 
with  soap,  whilst  waters  containing  larger  quantities  are 
termed  "  hard,"  since  they  form  a  curd  with  soap,  a  more  or 
less  considerable  quantity  of  the  soap  being  wasted  in 


8  WATER  SUPPLIES 

decomposing  the  lime  and  magnesia  compounds  before  a 
lather  will  form.  The  hardness  is  usually  expressed  by 
chemists  in  degrees,  each  degree  corresponding  to  one  grain 
of  carbonate  of  lime,  or  its  equivalent  of  other  lime  or 
magnesia  salts  in  the  gallon  of  water.  As  previously  stated, 
the  carbonates  are  thrown  out  of  solution  by  boiling,  and 
the  water  then  becomes  softer  in  proportion  to  the  amount 
of  these  salts  so  removed.  This  removable  hardness  is 
called  "  temporary,"  whilst  the  hardness  remaining  after 
boiling,  and  which  is  chiefly  due  to  the  presence  of 
sulphates  of  lime  and  magnesia,  is  called  "  permanent/' 
Waters  under  5°  or  6°  of  hardness  may  be  considered 
"  soft,"  those  exceeding  12°  "  hard."  The  advantages  and 
disadvantages  of  "  soft  "  water  will  be  fully  discussed  later, 
when  all  the  points  bearing  upon  the  selection  of  a  source 
of  supply  are  being  considered. 

Water  not  only  takes  up  gases  from  the  air,  mineral  and 
organic  matter  from  rocks  and  soil,  but  certain  waters  act 
upon  and  dissolve  traces  of  the  metals — lead,  iron,  and 
zinc — of  which  cisterns  and  pipes  are  generally  made.  A 
chemically  pure  water  would  probably  have  no  action 
whatever  upon  these  metals  if  also  chemically  pure ;  but  as 
natural  waters  are  never  absolutely  pure,  nor  the  metals 
free  from  impurities,  under  certain  conditions  chemical  or 
electrolytic  action  is  set  up,  and  the  metals  are  acted  upon. 
The  presence  of  any  of  these  metals  in  a  drinking  water  is 
objectionable,  but  traces  of  lead  are  far  more  dangerous 
than  traces  of  iron  or  zinc,  since  lead  is  not  only  more 
poisonous,  but  is  also  a  cumulative  poison — that  is,  the  lead 
tends  to  accumulate  in  the  system,  and  as  the  quantity 
stored  increases  so  also  does  its  poisonous  action  become 
more  marked.  The  medical  officer  to  the  Local  Govern- 
ment Board,  in  his  report  for  the  year  1890,  stated  that 
"  upwards  of  600,000  persons  in  the  West  Riding  of 
Yorkshire  alone  appear,  from  the  statements  of  medical 
officers  of  health,  to  be  at  one  or  another  time  liable  to 


WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC.          g 

lead-poisoning  by  the  drinking-water  supplied  to  their 
populations."  The  districts  of  Lancashire  and  West  York- 
shire appear  to  suffer  more  than  others  from  this  form  of 
poisoning,  and  certain  medical  inspectors  were  deputed  to 
conduct  such  "  chemical  and  bacteriological  "  studies  as 
were  most  likely  to  lead  to  the  discovery  of  the  conditions 
under  which  waters  can  acquire  the  power  of  dissolving 
lead.  Unfortunately  the  cholera  scare  interfered  with  the 
investigation,  and  it  is  not  yet  completed.  Dr.  Sinclair 
White  found  that  all  the  waters  he  examined  which  acted 
upon  lead  were  distinctly  acid,  and  at  Sheffield  the  solvent 
action  of  the  water  varied  directly  with  the  acidity.  When 
this  acidity  was  neutralised  in  any  way,  as  by  the  addition 
of  limestone  (carbonate  of  lime),  or  carbonate  of  soda,  the 
water  no  longer  attacked  the  metal.  He  believes  that  the 
acid  is  derived  from  the  decaying  peat  on  the  moors  upon 
which  the  water  is  collected.  Other  observers  think  that 
the  acidity  is  due  to  sulphuric  acid,  which  is  present  in  the 
air  in  immense  quantities  in  districts  where  certain  iron 
and  other  ores  are  smelted,  and  where  inferior  kinds  of 
coal  (containing  pyrites)  are  consumed.  Assuming  it  to 
be  true  that  the  rain  can  in  this  manner  acquire  some 
degree  of  acidity,  it  may  be  questioned  whether  it  is  ever 
possible  for  it  to  acquire  an  amount  of  acid  in  any  way 
comparable  with  the  extreme  amount  found  to  be  present 
in  certain  moorland  waters.  Moreover,  the  gathering 
grounds  yielding  the  most  acid  waters  are  by  no  means 
always  situated  the  most  closely  to  such  manufacturing 
areas. 

Others,  again,  believe  that  the  acidity  of  moorland  waters 
arises  from  the  slow  oxidation  of  iron  pyrites  in  the  soil. 
That  iron  pyrites,  in  the  presence  of  oxygen  and  moisture, 
forms  sulphuric  acid  is  of  course  a  fact  familiar  to  all 
chemists.  But  it  may  be  doubted  whether  the  distribution 
of  iron  pyrites  on  moorland  gathering  grounds  is  such  as  to 
render  this  explanation  a  generally  applicable  one, 


io  WATER  SUPPLIES 

The  comparative  absence  of  silica  and  carbonate  of  lime 
has  been  suggested  as  the  cause  of  the  action  of  moorland 
waters  on  lead,  but  it  is  tolerably  certain  that  there  are 
accompanying  factors,  and  that  the  absence  of  these  sub- 
stances bears  no  direct  causal  relationship  to  plumbo- 
solvency. 

Mr.  W.  H.  Power,  as  far  back  as  1888,*  suggested  that  as 
chemistry  had  signally  failed  to  give  us  a  clear  insight  into 
the  antecedent  cause  of  the  acidity  of  moorland  waters,  the 
study  of  the  question  from  the  biological  point  of  view 
might  prove  of  service. 

Again,  in  1895, f  Mr.  Power  pointed  out  that  his  original 
forecast  had  in  great  measure  been  confirmed  by  the 
labours  of  the  experts  employed  by  the  Local  Government 
Board  to  study  the  question.  In  summarising  the  work 
done  up  to  the  time  of  writing  his  report,  Mr.  Power  drew 
attention  to  the  following  facts  and  inferences  :  Moorland 
waters  when  they  have  left  the  moor,  when  they  have 
become  divorced  as  it  were  from  the  peat,  have  completed 
their  history  so  far  as  acidity  is  concerned.  Thus  the 
storage  of  such  waters  under  a  variety  of  conditions  never 
leads  to  any  increase  of  acidity,  and  usually  there  is  an 
appreciable  decrease.  Moist  peat  soil  is  invariably  acid  in 
reaction,  and  certain  microbes  isolated  from  peat  possess 
the  power  when  grown  in  a  neutral  decoction  made  soldi/ 
from  peat  of  rendering  the  liquid  acid  and  giving  it  as  well 
plumbo-solvent  ability.  The  inference  is  that  the  acidity 
and  plumbo-solvent  ability  observed  in  moorland  waters  is 
possibly  (if  not  probably)  to  be  traced  to  the  washing  out 
of  the  products  of  the  life  processes  of  these  bacteria  from 
the  substance  of  peat  soil.  Further,  Mr.  Power  laid 
considerable  stress  on  the  value  of  the  observations  carried 

*  Supplement  by  the  medical  officer  to  the  seventeenth  Annual 
Keport  of  the  Local  Government  Board,  1888. 

f  Report  of  the  medical  officer,  Local  Government  Board,  1893-4. 
"  Lead  Poisoning  by  Moorland  Waters,"  by  W.  H.  Power,  F.R.S, 


WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC.         n 

out  on  the  Burnmoor  moorland  gathering  ground  in  their 
negative  aspects.  Thus  he  says  :  "  They  (i.e.  the  Burnmoor 
observations)  tend  to  indicate,  by  a  plurality  of  determina- 
tions spread  over  many  months,  not  only  that  the  ability  of 
a  particular  water  to  dissolve  lead  is  closely  associated  with 
acidity  of  such  water,  but  also  that  this  action  in  regard 
of  lead  is  not  to  be  so  associated  with  any  other  observed 
condition  to  which  the  water  was  liable."  Dr.  Scatterty, 
M.O.H.,  Keighley  (Public  Health,  April,  1895),  also  pointed 
out  this  acid-producing  property  of  peat,  and  referred  to 
the  acid  so  produced  as  the  cause  of  the  plumbo-solvent 
action  of  moorland  waters. 

Dr.  Garrett,  as  the  result  of  a  long  series  of 
experiments,  considers  the  action  as  "  primarily  an 
oxidising  one,"  dependent  upon  the  presence  of 
nitrates  or  nitrites.  A  very  minute  quantity  of 
these  substances,  he  says,  appears  capable  of  setting 
up  this  action,  which  is  further  assisted  by  the  presence  of 
chlorides.  Acid  waters  freely  dissolve  oxide  of  lead  so 
formed,  hence  "  the  power  exhibited  ...  by  waters  of 
acid  reaction,  of  taking  lead  into  solution  when  they  are 
placed  in  contact  with  the  metal,  is  easily  explained." 
Whatever  may  be  the  nature  of  the  action  which  takes 
place,  the  waters  which  act  most  freely  on  lead  are  "  soft  " 
waters,  such  as  rain  water,  upland  surface-water,  and  the 
waters  of  certain  lakes ;  and  if  the  uplands  from  which  the 
water  is  collected  be  covered  with  peat,  the  plumbo-solvent 
action  of  the  water  will  at  certain  seasons  be  most  energetic. 
Certain  hard  waters  from  the  Bagshot  Sands  act  upon 
lead,  but  all  those  which  I  have  examined  either  con- 
tained no  carbonate  of  lime,  or  less  than  three  grains  per 
gallon — that  is,  the  hardness  was  entirely,  or  almost 
entirely,  of  a  "  permanent  "  character.  Certain  exception- 
ally soft  deep-well  waters  found  in  Essex  have  no  action 
upon  lead,  but  though  almost  free  from  carbonate  of  lime, 
they  contain  a  considerable  amount  of  carbonate  of  soda, 


12  WATER  SUPPLIES 

which  renders  the  water  alkaline,  and  so  produces  the  same 
effect  as  the  carbonate  of  lime.  The  introduction  into  any 
water  of  four  or  five  grains  of  carbonate  of  lime  per  gallon 
(as  by  filtration  through  beds  of  chalk  or  limestone),  or  its 
equivalent  of  carbonate  of  soda,  effectually  prevents  any 
action  upon  lead ;  not  only  so,  but  such  waters  cause  the 
formation  of  a  deposit  upon  the  surface  of  the  metal  of  some 
compound,  which  resists  for  a  time  the  action  of  the 
untreated  water. 

Whilst  the  presence  of  lead  can  only  be  discovered  by  the 
application  of  chemical  tests  to  the  water,  or  surmised  from 
the  symptoms  of  lead  poisoning  amongst  those  who  use  it 
(since  it  affects  neither  the  taste  nor  appearance),  the 
presence  of  iron  derived  from  the  action  of  the  water  upon 
a  pipe  or  cistern  is  detected  at  once  by  the  water  exhibiting 
a  more  or  less  marked  turbidity  and  depositing  upon 
standing  a  little  rust-coloured  sediment.  The  amount  of 
iron  actually  in  solution  'is  always  infinitesimal,  the  com- 
pound of  iron  formed  by  the  action  of  the  water  (or  its 
gaseous  and  saline  constituents)  upon  the  metal  being 
practically  insoluble,  and  if  filtered  such  water  is  in  no  way 
deleterious  to  health.  The  unfiltered  water,  however,  has 
an  unsightly  appearance  (from  the  suspended  oxide)  and 
will  iron-mould  clothes  if  used  for  washing.  The  action 
diminishes  after  a  time  as  the  pipes  become  coated  with 
oxide,  but  probably  never  entirely  ceases.  As  this  action 
can  be  entirely  prevented  by  using  pipes  or  cisterns  coated 
inside  with  some  "  protective  "  (vide  Chapter  XXI.),  such 
should  always  be  used. 

Waters  which  act  on  lead  appear  also  to  have  the  power 
of  acting  upon  zinc,  and  of  forming  poisonous  compounds 
which  dissolve  freely  in  the  water.  As  the  physical 
characters  of  the  water  are  not  altered,  the  presence  of  the 
metal  may  remain  unsuspected,  unless  some  obscure  form 
of  illness  leads  the  medical  attendant  to  have  it  examined. 
When  water  which  contains  an  appreciable  amount  of  zinc 


WATER,  ITS  COMPOSITION,  PROPERTIES,  ETC.         13 

is  heated  in  an  open  vessel,  before  it  commences  to  boil  an 
iridescent  film  is  observed  upon  the  surface,  sometimes 
giving  rise  to  the  impression  that  the  water  is  "  greasy." 
Waters  acting  upon  zinc  should  not  be  stored  in  zinc  or 
galvanised  iron  vessels,  or  passed  through  galvanised  iron 
pipes.  In  a  few  instances  I  have  come  across  waters  which 
had  an  appreciable  action  upon  copper,  and  cases  are 
recorded  of  water  used  for  domestic  purposes  corroding 
brass  fittings  and  becoming  contaminated  with  the 
constituents  of  the  alloy. 

Waters  containing  no  deleterious  organic  matters,  and 
only  such  mineral  matters  as  neither  from  their  quality  nor 
quantity  are  objectionable,  may  be  considered  as  pure  from 
the  hygienic  point  of  view.  If  the  mineral  matters  are  in 
excess,  or  deleterious  or  objectionable  organic  sub- 
stances are  also  present,  the  water  is  impure.  Where 
the  mineral  constituents  are,  either  from  their  quan- 
tity or  quality,  sufficiently  potent  to  confer  medicinal 
qualities  upon  the  water,  it  is  called  a  mineral  water. 
Such  waters,  if  containing  iron,  are  "  ferruginous "  or 
"  chalybeate " ;  if  containing  odorous  sulphur  com- 
pounds, "  sulphuretted " ;  if  containing  sulphate  of 
magnesia  or  other  mild  purgatives,  "  aperient,"  etc.  These 
waters  are,  of  course,  useless  for  domestic  purposes, 
and  therefore  require  no  further  reference  here. 

Potable  waters  may  be  divided  into  the  following  classes, 
according  to  the  source  from  which  they  are  directly 
obtained  : 

Rain  water. 

Surface  water  (including  lake  and  pond  waters). 

Subsoil  water. 

Deep-well  water. 

Spring  water. 

River  water. 

Each  of  these  sources  will  be  separately  considered. 


CHAPTER  II. 

RAIN  AND  RAIN  WATER. 

WHEN  water  is  boiled  in  a  suitable  vessel  and  the  steam 
passed  through  some  form  of  cooling  apparatus  the  vapour 
.  is  condensed,  and  water  flows  from  the  open  end  of  the 
cooled  tube.  This  is  the  process  of  distillation,  and  water 
so  obtained  is  called  "distilled  water."  As  the  water 
approaches  the  boiling  point  the  less  soluble  gases  are 
evolved,  but  the  more  soluble  ammonia  (if  present)  distils 
over  with  and  is  contained  in  the  first  portions  of  the 
distilled  water.  The  saline  constituents  of  the  water,  being 
non-volatile,  remain  behind  in  the  vessel  in  which  the 
water  is  being  boiled.  As  stated  in  the  last  chapter,  water 
slowly  evaporates  into  the  air  at  all  temperatures,  and  at 
10°  C.  (50°  F.)  1  cubic  yard  of  air  can  contain  150  grains 
of  water,  at  21°  C.  (70°  F.)  about  twice  this  amount,  and 
at  0°  C.  (32°  F.)  about  half.  If,  therefore,  1  cubic  yard 
of  air  saturated  with  moisture  at  21°  C.  be  cooled  to  0°, 
it  would  deposit  about  225  grains  of  water  in  the  form  of 
dew  or  rain.  The  ocean  has  been  compared  to  a  boiler, 
the  sun  to  a  furnace,  and  the  atmosphere  to  a  vast  still. 
The  cooler  air  of  the  higher  atmosphere  and  of  colder  zones 
acts  as  the  condenser,  causing  the  precipitation  of  the 
distilled  water  as  rain.  About  three-fourths  of  the  earth's 
surface,  or  145,000,000  of  square  miles,  is  covered  with 
water,  three-fifths  of  which  is  south  of  the  equator.  The 
surface  of  the  water  is  heated  by  the  direct  rays  of  the  sun, 
and  evaporation  is  rapid,  especially  in  tropical  regions. 

(H) 


RAIN  AND  RAIN  WATER  15 

Somerville  estimates  that  "  186,240  cubic  miles  of  water 
are  annually  raised  from  the  surface  of  the  globe  in  the 
form  of  vapour,  chiefly  from  the  inter-tropical  seas.  The 
evaporation  over  the  surface  of  the  ocean  is  so  great  that, 
were  it  not  restored,  it  would  depress  its  level  about  5 
feet  annually."  Ansted  says  that  "  about  7,000  ft)  weight 
of  water  are  evaporated  every  minute,  on  an  average, 
throughout  the  year  from  each  square  mile  of  ocean."* 
Besides  this  evaporation  from  the  ocean,  evaporation  is 
constantly  going  on  from  the  surface  of  the  land,  the 
amount  varying  with  the  season  and  climate,  the  nature  of 
the  soil,  and  the  character  of  the  vegetation.  When  dis- 
cussing the  amount  of  water  obtainable  from  various 
watersheds,  this  question  of  evaporation  will  receive  further 
consideration.  According  to  Somerville  "  the  vapour  from 
the  great  reservoirs  at  the  equator  and  the  southern  hemi- 
sphere is  wafted  by  the  south-east  trade  wind  in  the  upper 
regions  of  the  atmosphere  till  it  comes  to  the  calms  of 
Cancer,  where  it  sinks  down  and  becomes  a  south  and 
south-west  surface  wind,  and  then  the  condensation  begins 
that  feeds  all  the  great  rivers  of  the  world."  Moisture-laden 
air  if  cooled  sufficiently  will  give  up  a  portion  of  its  water 
in  the  form  of  mist  (cloud)  or  rain,  the  amount  of  water 
condensed  varying  with  the  degree  of  saturation  of  the  air 
in  the  first  instance,  and  the  extent  to  which  the  tempera- 
ture is  reduced.  This  cooling  is  produced  in  three  ways — 
(a)  by  the  ascent  into  the  higher  regions  of  the  atmosphere, 
the  temperature  falling  about  3°  C.  for  every  thousand 
feet  ascended,  (b)  by  contact  with  cold  surfaces,  as  of  the 
sides  of  mountains,  and  (c)  by  admixture  with  colder  air. 
The  first  cause  is  by  far  the  most  important,  the  last  can 
only  under  comparatively  rare  circumstances  be  the  cause 
of  rain.  The  importance  of  the  second  is  sometimes  over- 

*  "  All  the  coal  which  men  could  dig  from  the  earth  in  many  centuries 
would  not  give  out  enough  heat  to  produce,  by  the  evaporation  of  water, 
the  earth's  rain  supply  for  a  single  year." — Symons'  Met.  Mag.,  vol.  v. 


1 6  WATER  SUPPLIES 

rated,  since  to  it  is  often  attributed  the  excessive  rainfall 
in  hilly  districts  and  mountainous  regions.  The  effect  of 
the  hills  is  principally  to  direct  the  air  currents  impinging 
upon  them  upwards,  and  therefore  into  colder  regions. 
The  lowest  stratum  of  air  only  can  be  chilled  by  contact 
with  the  ground.  As  Eaton  *  points  out,  "  if  this  contact 
with  the  cold  ground  were  sufficient  to  cause  rain,  we  should 
invariably  have  rain  when  in  the  winter  months  a  warm 
and  saturated  south-west  wind  succeeded  a  frost,  as  long 
as  the  ground  remained  unthawed,  instead  of  a  thin  surface 
fog,  as  usually  obtains."  In  the  British  Islands  the 
westerly  are  the  chief  rain-bearing  winds.  As  the  west 
coast  is  mountainous,  such  winds  are  directed  upwards  by 
contact  with  the  hillsides;  the  cold  produced  by  the 
expansion  first  condenses  the  vapour  into  cloud  and  finally 
into  rain.  Most  of  the  rain  is  deposited  on  the  western 
slopes ;  the  clouds,  having  passed  over  the  range  of  hills, 
tend  to  sink,  become  warmer,  and  disappear.  Thus  the 
westerly  winds  are  comparatively  dry  by  the  time  the 
opposite  coast  is  reached,  and  as  easterly  winds  blowing 
over  the  European  Continent  usually  contain  but  little 
moisture,  the  rainfall  on  the  east  coast  is  far  less  than  that 
upon  the  west.  In  England,  east  of  a  line  extending  from 
Shields  to  Reading  and  north  of  the  Thames,  the  average 
rainfall  per  annum  is  only  about  23  inches;  along  the 
south  coast  it  is  about  35  inches ;  whilst  in  the  mountainous 
districts  of  Cumberland,  Westmoreland,  Wales,  and  Devon- 
shire, the  average  exceeds  75  inches.  Up  to  about  2,000 
feet  the  amount  of  rainfall  increases  with  the  elevation; 
above  this  level,  the  clouds  having  already  deposited  most 
of  the  moisture  they  originally  contained,  the  amount 
decreases,  or  at  least  no  longer  increases.  Where  the  hills 
do  not  reach  2,000  feet,  and  where  they  are  cut  through 
by  valleys,  more  rain  is  deposited  on  the  lee  side  of  the 

*  Proc.  Brit.  Met.  Soc.,  1861. 


RAIN  AND  RAIN  WATER  17 

hills  and  over  the  country  opened  out  by  the  valleys.  The 
following  gaugings  by  Mr.  Bateman,  taken  along  the  line  of 
the  Rochdale  Canal  across  the  Pennine  Chain  *  "  show  to 
a  marked  degree  the  abstraction  of  moisture  caused  by  the 
intervention  of  a  range  of  hills  "  :  — 

ANNUAL  RAINFALL. 

At  Rochdale        .         «        .  34-25  inches     At  foot  of  western  slope. 

White  Holmes,  Blackstone^  52<55  1,200  feet  above  sea-level. 

edge          ^      .        .        ./ 

Toll  Bar  „  53-16  „          1,000  feet  above  sea-level. 

Black  House  „  51-80  ,,          1,000  feet  above  sea-level. 

Sowerby  Bridge  .         .         .  29-85  „  300  feet  above  sea-level. 

at  foot  of  eastern  side  of  the  hills. 

Over  some  five-and-a-half  millions  of  square  miles  of  the 
land  surface  of  the  globe  rain  seldom  or  never  falls — (the 
deserts  of  Sahara,  Gobi,  Kalahari,  the  interior  of  Australia, 
etc.).  Near  the  equator  the  rainfall  is  almost  perpetual. 
At  Cherraponjee,  in  the  Khasia  Hills,  in  Assam,  the 
average  rainfall  is  over  400  inches.  Probably  the  wettest 
district  in  England  is  the  Stye  Pass,  in  the  Cumberland 
Hills,  where  about  200  inches  fall  annually,  the  average 
over  the  whole  of  England  being  about  30  inches.  Speaking 
generally,  the  rainfall  varies  with  the  latitude,  altitude, 
distance  from  the  sea,  direction  of  the  prevailing  winds, 
extent  of  forests,  and  position  with  reference  to  mountain 
ranges. 

The  rainfall  also  varies  greatly  at  certain  seasons.  Over 
nearly  the  entire  sub-tropical  region  winter  is  the  rainy 
season.  According  to  Scott  j-  the  exceptions  are  "  the 
eastern  coast  of  the  great  continents,  as  China  and  the 
eastern  states  of  the  Union,  which  enjoy  a  sort  of  monsoon 
rain  in  the  height  of  the  summer.  Natal  in  Africa  and 
the  Argentine  Republic  come  under  the  same  category. 

*  De  Ranee,  The  Water  Supply  of  England  and  Wales, 
f  Elementary  Meteorology. 

2, 


1 8 


WATER  SUPPLIES 


All  these  countries  receive  abundant  rains  at  the  period 
most  favourable  for  the  growth  of  crops.  .  .  .  The  countries 
with  winter  rains  and  summer  droughts  must  have  recourse 
to  irrigation  to  water  their  fields."  In  other  regions 
farther  north,  rain  falls  at  all  periods  of  the  year,  as  in  the 
British  Isles.  On  the  west  coast  most  rain  falls  in  January, 
but  on  the  opposite  coast  September,  October  and  Novem- 
ber are  the  wettest  months.  The  mean  monthly  rainfall 
at  Kew,  Greenwich,  and  in  Massachusetts  for  various 
periods  is  given  in  the  subjoined  table :  — 


Kew. 

Kew. 

Greenwich. 

Massachusetts.  * 

1813-72. 

1865-80. 

1881-90. 

January  . 

1-9 

2-2 

1-3 

3-7 

February 

1-5 

1-7 

1-8 

3-6 

March 

1-5 

1-3 

1-3 

3-9 

April 

1-7 

1-85 

1-3 

3-3 

May 

2-1 

1-6 

1-6 

3-3 

June 

2-0 

2-1 

1-6 

3-3 

July 

2-3 

2-4 

2-2 

3-8 

August     . 

2-3 

2-2 

1-6 

4-1 

September 

2-35 

2-5 

1-7 

3-0 

October   . 

2-7 

2-5 

1-9 

3-7 

November 

2-3 

1-9 

2-0 

3-9 

December 

1-9 

2-2 

1-4 

3-5 

The  variation  in  the  rainfall  in  any  given  district  in 
different  years  and  in  different  parts  of  the  year  has  an 
important  bearing  upon  the  question  of  water  storage,  and 
will  be  considered  in  the  section  treating  of  that  subject. 

A  precise  knowledge  of  the  amount  of  rainfall  is 
absolutely  necessary  where  the  total  amount  of  water  falling 
upon  a  given  area  has  to  be  ascertained,  and  this  knowledge 
can  only  be  obtained  by  careful  collection  and  registration. 
Such  records  also,  if  properly  kept,  are  of  the  greatest 
service  in  enabling  approximate  estimates  to  be  made  of 

*  Average  deduced  from  long-continued  observations  in  various  parts 
of  the  State.  Report  on  Water  Supplies,  1889-90. 


RAIN  AND  RAIN  WATER  ig 

the  amount  of  water  which  can  be  collected,  and  for  com- 
paring the  rainfall  over  different  areas.  It  is  very  desirable, 
therefore,  that  some  uniform  plan  of  collection  and 
registration  should  be  adopted.  The  Royal  Meteorological 
Society  gives  to  its  observers  .the  following  instructions 
(Hints  to  Meteorological  Observers,  with  Instructions  for 
Taking  Observations)  :  — : 

"  Rain-gauge. — The  rain-gauge  should  be  made  of  copper, 


FIG.  1. — Snowdon  Rain-guage. 

and  have  a  circular  funnel  of  either  5  or  8  inches  diameter, 
with  a  can  or  bottle  inside  to  collect  the  water.  It  is  very 
desirable  that  it  should  be  of  the  Snowdon  pattern — that 
is,  with  a  6-inch  cylinder  and  a  sharp  brass  rim  (Fig.  1). 

"  It  should  be  set  in  an  open  situation,  away  from 
trees,  walls,  and  buildings — at  the  very  least  as  many  feet 
from  their  base  as  they  are  in  height — and  it  should  be  so 


20  WATER  SUPPLIES 

firmly  fixed  that  it  cannot  be  blown  over ;  the  top  of  the 
rim  should  be  one  foot  above  the  ground,  and  must  be  kept 
quite  level. 

"  The  measurement  of  the  rainfall  is  effected  by  pouring 
out  the  contents  of  the  water  of  the  bottle  or  can  into  the 
glass  measure,  which  must  be  placed  quite  vertical,  and 
reading  off  the  division  to  which  the  water  rises;  the 
reading  is  to  be  taken  midway  between  the  two  apparent 
surfaces  of  the  water.  The  glass  measure  is  usually 
graduated  to  represent  tenths  and  hundredths  of  an  inch, 
and  holds  0.50  inch  of  rainfall.  Each  division  represents 
the  one-hundredth  of  an  inch,  the  longer  divisions  five- 
hundredths,  and  the  long  divisions,  having  figures  attached, 
tenths  of  an  inch.  If  there  be  more  than  half  an  inch  of 
rain,  two  or  more  measurements  must  be  made,  and  the 
amounts  added  together.  The  complete  amount  should 
always  be  written  down  before  the  water  is  thrown  away. 
The  gauge  must  be  daily  examined  at  9  A.M.,  and  the 
rainfall,  if  any,  entered  to  the  previous  day ;  if  none  be 
found,  a  line  or  dash  should  be  inserted  in  the  register.  It 
is  desirable  that  very  heavy  rains  should  be  measured 
immediately  after  their  occurrence,  entering  the  particulars 
in  the  remarks,  but  taking  care  that  the  amount  is  included 
in  the  next  ordinary  registration. 

"  Snow. — When  snow  falls,  that  which  is  collected  in  the 
funnel  is  to  be  melted  and  measured  as  rain.  This  may 
quickly  be  done  by  adding  to  the  snow  a  measured  quantity 
of  warm  water,  and  afterwards  deducting  the  quantity 
from  the  total  measurement.  If  the  snow  has  drifted,  or 
if  the  funnel  cannot  hold  all  that  has  fallen,  a  section  of 
the  snow  should  be  obtained  in  several  places  where  it  has 
not  drifted  by  inverting  the  funnel,  turning  it  round,  lifting 
and  melting  what  is  enclosed.  The  section  should,  if 
possible,  be  taken  from  the  surface  of  a  flat  stone." 

In  mountainous  districts,  and  for  waterworks  purposes, 
in  which  it  is  only  necessary  to  make  weekly  or  monthly 


RAIN  AND  RAIN  WATER  21 

observations,  a  special  form  of  rain-gauge  must  be  used.* 
Mr.  Symons'  pattern  is  admirably  adapted  for  this  purpose 
(Fig.  2).  The  cylinder  in  which  the  water  is  collected  will 


FIG.  2. — Symons'  Mountain  Rain-guage. 

contain  48  inches  of  rain,  and  by  aid  of  a  graduated 
rod  and  float,  readings  may  be  taken  to  one-tenth  of  an 
inch.  The  rod  is  detached  and  only  introduced  when  an 

*  MM.  Richard  Freres  of  Paris  make  a  self-registering  rain-gauge. 


22  WATER  SUPPLIES 

observation  is  being  made.  In  districts  where  the  annual 
rainfall  does  not  exceed  40  inches,  the  collecting  cylinder 
may  be  of  smaller  capacity.  If  the  area  of  the  mouth  of 
the  funnel  be  twice  that  of  the  cylinder,  the  float  will  rise 
2  inches  for  each  inch  of  rain,  and  the  accuracy  of  the 
readings  is  increased. 

One  inch  of  rainfall  corresponds  to  nearly  4|  gallons  per 
square  yard,  or  22,620  gallons  per  acre.  If  1  inch  of  rain 
fell  upon  some  impervious  surface,  such  as  a  roof,  covering 
say  10  square  yards  of  ground,  the  amount  of  water  which 
could  be  collected,  providing  none  were  lost  by  evapora- 
tion or  from  any  other  cause,  would  be  46|  gallons.  To 
obtain  anything  approaching  this  amount,  however,  the 
rain  would  have  to  be  heavy  and  continuous.  If  it  fell  in 
a  series  of  slight  showers  spread  over  any  considerable 
interval,  and  especially  in  hot  weather,  only  a  very  small 
proportion  indeed  would  be  collected — nearly  all  would  be 
lost  by  evaporation.  When  the  rain  falls  upon  more  or 
less  pervious  soil  covered  with  vegetation,  it  is  only  the 
heavy  rains  or  long-continued  showery  weather  which 
yields  sufficient  water  to  percolate  into  the  subsoil  to  feed 
the  springs  and  raise  the  level  of  the  subsoil  water  (vide 
Chapter  IV.).  The  total  rainfall  and  the  rainfall  available 
for  water  supplies  are  therefore  not  identical  terms. 

Rain  water  collected  from  a  clean,  impervious  surface  in 
the  open  country  is  the  purest  of  natural  waters.  In 
passing  downwards  through  the  air,  however,  it  not  only 
takes  up  a  proportion  of  the  gaseous  constituents,  but  also 
washes  from  the  air  all  floating  impurities,  whatever  their 
nature.  The  rain  which  first  falls  always  contains  the 
largest  proportion  of  these  impurities.  In  the  neighbour- 
hood of  towns  the  rain  contains  soot,  sulphuric  acid,  and 
other  matters  derived  from  the  combustion  of  coal,  together 
with  ammoniacal  salts,  nitrates,  and  albuminous  matters 
derived  from  decomposing  animal  and  vegetable  sub- 
stances, and  the  exhalations  from  the  bodies  of  men  and 


RAIN  AND  RAIN  WATER  23 

animals.  Minute  traces  of  these  substances,  together  with 
common  salt  (derived  from  the  sea)  and  various  micro- 
organisms, are  found  in  all  rain  waters. 

One  gallon  of  rain  contains  on  an  average  8  cubic  inches 
of  gases,  of  which  about  one-third  is  oxygen  and  two-thirds 
nitrogen.  The  carbonic  acid  amounts  only  to  about  two 
per  cent,  of  the  mixed  gases. 

Dr.  Angus  Smith,  in  his  work  on  Air  and  Eain,  states 
that  rain  from  the  sea  contains  chiefly  common  salt;  that 
the  sulphates  increase  inland  before  large  towns  are 
reached,  and  seem  to  be  the  products  of  decomposition, 
the  sulphuretted  hydrogen  from  organic  compounds  being 
oxidised  in  the  atmosphere ;  that  the  sulphates  rise  very 
high  in  large  towns  because  of  the  amount  of  sulphur  in 
the  coal  used,  as  well  as  to  decomposition;  that  when  the 
sulphuric  acid  increases  more  rapidly  than  the  ammonia, 
the  rain  becomes  acid;  that  free  acids  are  not  found  with 
certainty  where  combustion  or  manufactures  are  not  the 
cause ;  and  that  ammoniacal  salts  increase  in  the  rain  as 
towns  increase  :  they  come  partly  from  coal  and  partly  from 
decomposed  organic  substances.  The  observations  of  Dr. 
Miguel  at  Montsouris,  Paris,  on  the  micro-organisms  found 
in  rain,  prove  that  bacteria,  pollen,  spores  of  fungi, 
protococci,  etc.,  constantly  occur,  and  are  especially 
numerous  in  the  warmer  months;  and  in  the  first  showers 
after  a  long  spell  of  dry  weather  over  100,000  such  organ- 
isms may  occur  in  a  single  pint  of  rain  water. 

The  foregoing  remarks  refer  only  to  water  collected 
directly  in  clean  vessels.  If  the  rain  has  fallen  upon  a  roof 
it  may  become  seriously  contaminated  by  the  excrement  of 
birds,  decaying  vegetable  matter,  soot,  and  dust;  in  fact 
some  of  the  filthiest  waters  used  for  domestic  purposes 
which  I  have  examined  have  come  from  rain-water  tanks. 
The  solid  organic  matters  are  washed  from  the  roof  or  other 
collecting  surfaces  into  the  tanks;  these  undergo  further 
putrefactive  change,  the  products  formed  entering  into 


24  WATER  SUPPLIES 

solution  and  accentuating  the  pollution.  When  properly 
collected,  rain  water  can  be  stored  and  utilised  for  all 
domestic  purposes.  Since  it  never  contains  more  than  a 
trace  of  lime  salts  in  solution,  it  is  exceedingly  soft  and 
well  adapted  for  washing.  Its  taste  is  mawkish  and 
objectionable,  but  this  can  be  remedied  by  nitration ;  in 
fact  it  can  be  rendered  quite  palatable.  Rain  water, 
especially  in  certain  districts  where  manufacturing  towns 
abound,  is  frequently  distinctly  acid,  and  then  acts  freely 
on  various  metals.  It  is  not  safe,  therefore,  to  store  it  in 
lead,  zinc,  iron,  or  galvanised  iron  tanks.  Slate  tanks  may 
be  used,  but  if  the  joints  are  made  with  white  or  red  lead, 
the  angles  where  the  lead  is  exposed  should  be  filled  in  with 
cement.  This  not  only  prevents  the  lead  being  acted  upon, 
but  renders  the  jointing  more  secure  and  facilitates 
cleansing.  Earthenware  can  be  used  for  small  cisterns. 
Large  storage  tanks  may  be  built  of  brick,  and,  if  under- 
ground, should  be  well  puddled  outside  with  clay.  The 
bricks  should  be  set  with  hydraulic  lime  mortar  and  the 
inside  of  the  tank  lined  with  Portland  cement.  The  object 
of  these  precautions  is  not  only  to  prevent  the  rain  water 
wasting  by  leakage,  but  also  to  prevent  ground  water 
gaining  access.  Access  of  surface  water  must  also  be 
guarded  against  by  roofing  over  in  a  similar  manner.  By 
proper  collection  and  storage  of  the  rainfall  it  is  often 
possible  to  obtain  a  fairly  abundant  supply  of  good  water 
for  a  farm,  dwelling-house,  or  even  a  group  of  houses.  To 
effect  this,  three  conditions  are  necessary: — (1)  The  tank 
must  be  of  sufficient  size  to  store  all  the  available  rainfall, 
and  must  be  properly  constructed.  (2)  The  first  portion 
of  every  shower  which  washes  the  roof  or  other  collecting 
surface,  and  is  therefore  always  filthy,  must  not  be  allowed 
to  enter  the  storage  tank.  (3)  There  must  be  some  efficient 
system  of  filtration.  The  area  covered  by  the  average 
country  cottage  may  be  taken  at  35  square  yards,  and  the 
available  rainfall  collected  from  a  roof  cannot  safely  be 


RAIN  AND  RAIN  WATER  25 

estimated  at  more  than  half  the  total  rainfall.  Much  is 
lost  by  evaporation;  many  slight  showers  do  not  yield 
enough  water  to  reach  the  tank,  and  in  very  heavy  showers 
much  is  often  lost  by  the  water  running  over  the  eaves 
troughing,  or  over  the  ends  of  the  cottage  where  there  is 
no  spouting.  Assuming  the  rainfall  to  be  the  average, 
from  15  to  18  inches  could  be  collected.  This  would  yield 
for  the  year  about  3,200  gallons,  or  9  gallons  per  day.  It 
is  evident  that  this  would  not  be  sufficient  to  meet  all 
requirements;  but  even  in  the  worst  districts  there  are 
ponds  or  brooks  from  which  water  could  be  obtained  for 
slopping  purposes.  With  a  larger  roof  area,  of  course  a 
larger  amount  of  rain  water  would  be  available ;  but  as  few 
cottages  cover  an  area  of  40  square  yards,  about  9  gallons 
would  be  the  maximum  supply.  In  the  eastern  counties, 
where  the  rainfall  is  only  from  20  to  25  inches,  even  this 
amount  cannot  be  obtained,  but  in  districts  where  the 
rainfall  exceeds  the  average  more  could  be  collected.  The 
amount  of  water  required  on  farms  is  necessarily  larger 
than  in  cottages,  but  even  the  increased  collecting  area 
from  the  roof  of  the  house  and  outbuildings  would  not  give 
a  relatively  more  abundant  supply. 

As  the  water  is  in  constant  use,  the  storage  tank  need 
not,  of  course,  be  so  large  as  to  hold  at  one  time  the  whole 
of  the  amount  collected  during  the  year.  It  will  be 
sufficient  if  it  is  one-fourth  or  one-third  this  size — that  is, 
if  it  hold  a  rainfall  of  at  least  4  inches.  To  do  this,  the 
tank  must  have  a  capacity  of  3  cubic  feet  for  each  square 
yard  covered  by  the  roof  (not  of  actual  roof  area).  For  a 
country  cottage,  under  the  conditions  assumed  above,  the 
storage  space  must  be  105  cubic  feet.  This  would  be 
approximately  furnished  by  a  tank  6  feet  square  and  3 
feet  deep,  or  by  a  circular  tank  4  feet  8  inches  in  diameter 
and  6  feet  deep,  or  5  feet  in  diameter  and  5J  feet  deep. 
For  larger  roof  areas  the  size  of  the  storage  cistern  can 
easily  be  calculated. 


26  WATER  SUPPLIES 

To  separate  the  first  portion  of  the  rain  water,  Roberts' 
Rain-Water  Separator  may  be  used.  "  It  rejects  the  dirty 
and  stores  the  clean  water.  It  is  made  of  zinc,  upon  an 
iron  frame,  and  the  centre  part  or  canter  is  balanced  upon 
a  pivot.  It  is  self-acting,  and  directs  into  a  waste  pipe  the 
first  portion  of  the  rainfall,  which  washes  off  and  brings 
down  from  the  roofs  soot  and  other  impurities.  After  rain 
has  fallen  a  certain  time  the  separator  cants  and  turns  the 
pure  water  into  the  storage  tank."  The  vertical  form  is 
used  where  a  single  stack  pipe  carries  the  water  from  the 
roof  to  the  tank.  One  length  of  the  stack  pipe  is  removed, 
and  the  separator  is  inserted  and  fastened  to  the  side  of 
the  house.  When  a  building  is  provided  with  several  stack 
pipes  connected  by  an  underground  pipe  leading  to  the 
tank,  the  horizontal  form  should  be  used.  Various  sizes  of 
the  apparatus  are  made,  costing  from  £3  to  £6,  and  it  can 
be  fixed  by  any  intelligent  workman.* 

Fig.  3  shows  the  vertical  separator  in  the  position  that 
it  retains  when  running  foul  water  into  the  waste  pipe 
during  the  first  part  of  a  shower,  while  the  roof  is  yet 
dirty. 

Fig.  4  represents  it  when  it  has  canted  and  has  begun  to 
pass  the  pure  water  into  the  storage  tank. 

One  cannot  but  regret  to  see  in  rural  districts,  where 
water  famines  occur  almost  every  summer,  so  little  effort 
made  to  utilise  the  rainfall.  Any  kind  of  old  cask  or  tank 
is  considered  good  enough  in  which  to  store  the  rain,  and 
little  or  no  care  is  taken  to  so  securely  cover  the  receptacle 
as  to  prevent  impurities  getting  in.  Separators  are  not 
yet  generally  used,  and  therefore  the  water  which  is  col- 

*  The  author  some  time  ago  ordered  one  of  the  vertical  separators  to 
be  affixed  to  a  farmhouse.  Shortly  afterwards  he  received  a  complaint 
that  very  little  water  was  collected,  and  that  it  was  filthier  than  before. 
Upon  examination  he  found  that  the  workman  had  so  fixed  the  separator 
that  the  washings  of  the  roof  ran  into  the  tank,  whilst  the  pure  water 
ran  into  the  drain. 


RAIN  AND  RAIN  WATER 


27 


lected  is  more  or  less  filthy  from  the  first.  Occasionally 
there  is  some  pretence  to  filtration,  the  stack  pipe  dis- 
charging over  a  bed  of  sand  and  gravel  with  or  without 


FOUL 


FIG.  4. 


charcoal.  For  filtration  to  be  of  any  service  the  material 
must  be  so  fine  as  to  allow  the  water  to  pass  through  but 
slowly.  As  a  rule,  the  more  rapid  the  filtration  the  less 


28  WATER  SUPPLIES 

the  purification  (vide  Chapter  XIII.) ;  and  if  a  small  filter 
is  to  transmit  a  heavy  rainfall  it  is  evident  that  it  must  be 
too  coarse  to  be  more  than  a  strainer.  If  finer  material 
were  placed  in  such  a  filter  chamber,  a  considerable  portion 
of  every  heavy  rainfall  would  run  to  waste.  Where  a 
separator  is  used  comparatively  little  sediment  is  formed 
in  the  tanks,  and  the  water  is  sufficiently  clean  and  bright 
for  every  purpose  save  that  of  drinking.  For  table  pur- 
poses it  should  be  passed  through  some  good  form  of  filter, 
or  the  separated  rain  water  may  be  collected  as  it  falls  in 
the  receptacle  to  a  filter,  and  allowed  to  slowly  percolate 
through  the  filtering  media  into  a  collecting  tank,  from 
which  it  can  be  drawn  in  any  convenient  manner.  The 
filter  should  be  fitted  with  a  loose  cover,  so  that  whenever 
necessary  the  top  layer  of  sand  can  be  removed  and  replaced 
by  fresh,  or  the  filter  be  otherwise  cleaned.  The  receptacle 
receiving  the  water  from  the  "  separator "  should  be 
sufficiently  large  to  hold  J  an  inch  of  rainfall  upon  the 
whole  collecting  area. 

If,  instead  of  merely  utilising  the  roofs  of  buildings  for 
collecting  rain,  the  surface  of  a  portion  of  ground  be  ren- 
dered impervious,  any  quantity  of  water  may  be  obtained. 
In  many  cases  a  plot  of  ground  could  be  selected  at  such  an 
elevation  as  to  supply  the  mansion,  farm,  or  cottages  with 
water  by  gravitation,  so  saving  all  the  expense  of  pumps 
and  pumping.  Mr.  Eardley  Bailey  Denton,  M.I.C.E., 
writing  in  The  Field,  18th  June,  1887,  says,  "  1  inch  of 
rain  falling  on  the  surface  of  an  acre  is  equivalent  to  22,622 
gallons;  and  supposing  that  half  an  acre  of  land  be  set 
apart  and  rendered  impervious  for  the  collection  of  rain 
falling  on  it  during  the  six  winter  months,  the  amount 
collected  where  the  rainfall  is  least,  as  in  the  east  of 
England,  during  that  period  would  be  about  170,000  gallons 
(assuming  the  winter  rainfall  to  be  15  inches),  or  enough  to 
satisfy  the  wants  of  nearly  100  persons  for  a  period  of  three 
months  (an  exceptionally  long  drought)  at  20  gallons  a 


RAIN  AND  RAIN  WATER  29 

head  daily,  an  ample  quantity  for  all  individual  and  house- 
hold purposes.  Tanks  can  be  built  at  a  cost  varying  from 
£3  to  £5  per  1,000  gallons,  and  on  the  chalk  formation, 
where  scarcity  is  soonest  felt,  at  even  less  cost.  In  most 
cases  a  collecting  area  can  be  selected  free  from  contamina- 
tion. The  area  upon  which  the  water  would  be  collected 
need  merely  have  a  concrete  floor  with  cement  surface, 
railed  off  to  prevent  stock  running  over  it,  and  the  storage 
tank  may  be  constructed  underneath."  The  above  estimate 
of  the  amount  of  water  which  could  be  collected  does  not 
appear  to  be  excessive,  and  many  mansions  are  now  being 
satisfactorily  supplied  in  this  manner.  To  purify  the  water 
a  simple  filter  at  the  end  of  the  suction  pipe  in  the  under- 
ground tank,  supplemented  also  by  a  filter  along  the  course 
of  the  house  supply,  is  recommended.  This  second  filter  is 
fixed  below  the  house  cistern  in  an  accessible  position,  so 
that  the  contents  can  be  easily  cleaned.  Unfortunately 
this  plan  is  too  expensive  for  groups  of  cottages — that  is 
to  say,  the  cost  per  house  would  exceed  that  which  a 
Sanitary  Authority  can  compel  the  owner  to  expend  in 
obtaining  a  supply  (about  £8  per  cottage).  The  roof  area 
of  most  mansions  is  so  much  greater  per  inhabitant  than 
the  roof  area  of  cottages,  that  a  much  more  abundant 
supply  is  procurable.  Probably  20  square  yards  per  person 
is  an  average  in  a  mansion.  This  would  yield  about  1,500 
gallons  per  year,  or  4  gallons  per  head  per  day.  The  house 
cistern  should  be  capable  of  holding  about  a  week's  supply, 
and  be  filled  up  every  day.  The  need  for  a  cistern  so  large 
is  due  to  the  fact  that  the  demand  for  water  is  very 
unequal,  three  or  four  times  as  much  being  used  some  days 
as  others. 

The  rainfall  is  the  source  of  all  our  water  supplies;  but 
unless  caught  upon  artificially-prepared  surfaces,  such  as 
roofs  and  specially  prepared  cemented  surfaces,  it  is  not 
called  rain  water.  That  which  falls  upon  rocks,  either 
bare  or  with  little  vegetation.,  when  collected  is  called 


30  WATER  SUPPLIES 

"  upland  surface  water  "  ;  that  which  falls  upon  and  is 
collected  from  moors  is  "  moorland  water  "  ;  that  which 
runs  off  the  surface  of  pasture  lands,  "  surface  water  from 
cultivated  ground  "  ;  that  which  percolates  through  the 
surface  soil  into  a  pervious  subsoil  is  "  subsoil  water  "  ; 
whilst  that  which  travels  through  the  subsoil  under  im- 
pervious strata,  so  that  it  can  only  be  reached  by  boring 
through  such  strata,  is  "  subterranean  or  deep-well  water." 
Where  an  impervious  stratum  comes  to  the  surface  and 
throws  out  the  subsoil  water  from  the  pervious  stratum 
above,  a  land  spring  is  formed,  whilst  subterranean  water 
thrown  to  the  surface  in  any  way  forms  an  "  ascending  or 
deep  spring/'  The  waters  in  streams  may  be  derived  from 
any  one  or  more  of  these  sources;  river  water  is  usually  a 
mixture  of  all,  together  with  sewage  and  other  impurities 
received  from  the  towns  and  villages  along  its  course. 
Speaking  generally,  deep  springs  yield  the  purest  waters, 
and  rivers  the  most  impure;  they  may  be  arranged  in 
order  of  purity  as  follows  :  — 

Deep-spring  water. 

Subterranean  or  deep-  well  water. 

Upland  surface  water. 

Moorland  water. 

Subsoil  water  (if  distant  from  any  aggregation  of  houses). 

Land  springs. 

Surface  water  from  cultivated  ground. 

Kiver  water. 

Subsoil  water  under  villages  and  towns. 

The  R.P.C.  give  a  lengthy  Table  of  Analyses  of  carefully- 
collected  rain  water  (78  samples),  and  of  rain  water  as 
ordinarily  collected  and  stored  in  tanks  (8  samples).  The 
following  are  the  means  of  their  results. 


Tank  Water. 

Total  Solids      .         .         .  2-76          16-8  grs.  per  gallon. 

Nitric  Nitrogen         .         .  -004  -78       ,,  „ 

Chlorine  ...  -43  1-6 

Hardness  ...  -42  7-9 

Free  Ammonia         .         .  -50  1-15  pts.  per  million. 


CHAPTER    III. 

SURFACE    WATER. 

IGNEOUS,  Metamorphic,  Cambrian,  Silurian,  and  Devonian 
rocks  resemble  each  other  in  being  practically  impervious, 
and  very  slightly  acted  upon  by  water;   and  the  districts 
where    such    rocks    are    exposed    are    usually    wild    and 
mountainous,  and  in  Great  Britain  at  least  have  a  rainfall 
much  above  the  average.     Rain  falling  upon  such  surfaces 
rapidly  runs  off,  forming  rivulets  and  streams,  pools  and 
lakes,  the  water  from  which  differs  but  little  from  that  of 
the  rain  from  which  it  is  derived.     Certain  limestones  of 
the  Silurian  and  Devonian  systems,  however,  though  very 
compact  and  hard,  yield  an  appreciable  trace  of  carbonate 
of  lime  to  the  water,  causing  it  to  have  a,  hardness  of  from 
6  to   10  or  more  degrees.     The  hardest   rocks  undergo   a 
process  of  weathering,  by  the  exposure  of  their  surfaces  to 
the  action  of  the  air  and  water.     By  the  alternate  freezing 
and  thawing  of  water  in  the  minute  interstices,  the  super- 
ficial layers  become  disintegrated  and  yield  a  little  soluble 
matter  to  the  rain  falling  thereon.     If  the  surface  be  very 
steep,   the   debris   is   washed   away   as   formed;    if   not,    it 
gradually  accumulates,  until  there   is  sufficient  to   enable 
lichens  and  mosses  to  flourish.     The  decay  of  these  plants 
furnishes  mould  or  humus,  upon  which  larger  and  more 
highly-organised  plants  may  grow,  and  these  by  their  death 
and  decay  furnish  the  beds  of  peat  so  common  in  certain 
districts.     The  rain  falling  upon  such  plant-covered  surfaces 
is  in  part  retained,  some  being  returned  to  the  atmosphere 
by  evaporation  from  the  surface  of  tjie  soil,  and  from  the 

(31) 


32  WATER  SUPPLIES 

fronds  and  leaves  of  the  plants  covering  it,  the  remainder 
slowly  finding  its  way  to  lower  levels,  and  ultimately  into 
the  streams  and  pools.  Only  during  heavy  rains  will  any 
quantity  run  directly  off  the  surface.  From  the  bare  rocks, 
since  the  rain  immediately  flows  away,  comparatively  little 
is  lost  by  evaporation  or  absorption;  rivulets  and  streams 
are  quickly  formed  and  almost  as  quickly  disappear. 
Where  the  rocks  are  covered  with  vegetation  the  streams 
are  more  permanent,  though  fluctuating  greatly.  Much  of 
the  water,  being  retained  for  a  time  in  the  spongy  mass  of 
vegetable  de*bris  clothing  the  rock,  is  enabled  to  take  up  a 
certain  amount  of  organic  matter,  sufficient  frequently  to 
impart  a  brownish  colour  and  a  peculiar  bitter  "  peaty  " 
flavour.  These  impurities  are  solely  of  vegetable  origin, 
and  unless  excessive  in  quantity  appear  to  have  no  injurious 
effect  whatever  upon  the  health. 

The  igneous  rocks  of  Devon  and  Cornwall  yield  a  water 
containing  very  little  inorganic  matter;  but  as  peat  is 
abundant  in  these  districts,  the  organic  matter  derived 
therefrom  may  be  considerable.  Containing  little  or 
no  carbonate  of  lime,  they  usually  act  freely  upon 
lead  (vide  Tables  of  Analyses). 

The  Metamorphic,  Cambrian,  Silurian,  and  Devonian 
rocks,  exposed  in  Wales  and  neighbouring  counties, 
Westmoreland,  Cumberland,  Devon,  and  Cornwall, 
yield  water  very  similar  from  a  hygienic  point  of  view 
to  that  from  the  igneous  rocks.  The  metamorphic 
rocks  (quartz,  mica,  schist,  gneiss,  granite,  and  crystal- 
line limestone)  may  be  said  to  be  absolutely  impervious, 
as  may  also  the  slates  of  the  other  series.  The  sand- 
stones, however,  are  more  or  less  porous,  and  absorb 
some  portion  of  the  rainfall.  The  calcareous  rocks  of 
the  Silurian  and  Devonian  systems  are  exceedingly 
compact,  and  the  water  from  their  surface  is  but  little 
harder  than  that  from  the  non-calcareous  rocks. 


SURFACE   WATER  33 

The  non-calcareous  carboniferous  rocks  (Yoredale  rocks, 
millstone  grits  and  coal  measures)  occur  in  South 
Wales,  Derbyshire,  Yorkshire,  Lancashire,  and  North 
Staffordshire,  and  are  but  slightly  pervious.  A 
considerable  proportion  of  the  rainfall  on  the  slopes  of 
the  hills  finds  its  way  into  the  rivulets  and  streams, 
some  of  which  are  utilised  for  feeding  reservoirs  for 
supplying  many  of  our  manufacturing  towns  with 
water.  Certain  of  these  waters  are  exceedingly  soft, 
the  average  hardness  being  only  6°.  They  are  there- 
fore admirably  adapted  for  use  in  steam  boilers  and  for 
most  manufacturing  purposes.  They  are  frequently 
peaty  and  turbid,  but  when  carefully  filtered  usually 
form  satisfactory  domestic  supplies.  In  certain  dis- 
tricts the  water  is  frequently  acid,  and  then  acts 
powerfully  on  lead.  It  is  water  from  these  sources 
which  has  produced  the  extensive  prevalence  of  lead- 
poisoning  in  the  Lancashire  and  Yorkshire  towns. 

The  calcareous  carboniferous  rocks  (carboniferous  or  moun- 
tain limestone  and  limestone  shales)  of  Northumber- 
land, North  Yorkshire,  Lancashire,  and  Mid-Derbyshire 
yield  a  water  of  a  moderate  degree  of  hardness,  not  so 
well  adapted  for  many  manufacturing  purposes,  but 
not  too  hard  for  domestic  use,  and  free  from  any 
solvent  action  upon  lead.  The  beds  of  limestone  and 
sandstone  in  the  coal  measures  are  more  freely  acted 
upon  by  water,,  and  that  derived  from  the  surface  may 
be  excessively  hard,  even  exceeding  50°.  16°  is  given 
as  the  average.  When  the  hardness  is  excessive  the 
water  is,  of  course,  unsuitable  for  domestic  use  and  for 
most  manufacturing  purposes. 

The  secondary  rocks  "  stretch  across  England  from  the 
mouth  of  the  Tees  to  the  mouth  of  the  Exe,  with  a 
branch  running  to  the  mouth  of  the  Mersey."  The 
lias,  new  red  sandstone,  conglomerate  sandstone,  and 
magnesian  limestone  formations  yield  from  their 
3 


34  WATER  SUPPLIES 

uplands  a  water  closely  resembling  that  from  the 
mountain  limestone.  (Tables  I.  and  II.  include  analyses 
of  waters  from  all  the  above-mentioned  formations). 

Where  any  of  these  formations  are  covered  with  soil  in  a 
state  of  cultivation,  the  surface  water  is  often  much  altered 
in  character,  especially  if  the  soil  be  calcareous.  The 
hardness  is  then  considerably  increased.  All  are  liable  to 
contain  larger  traces  of  organic  matter,  some  of  which 
will  be  of  animal  origin.  Nitrates,  which  are  present  in 
infinitesimal  amount,  if  at  all,  in  water  from  barren  rocks, 
are  always  found,  and  may  occur  in  considerable  quantities, 
if  the  soil  be  manured.  The  chlorides  also  will  increase  in 
proportion  to  the  number  of  men  and  animals  living  upon 
the  gathering  ground.  In  this  country  the  amount  of 
chlorine  in  the  rainfall  varies  so  considerably  with  the 
distance  from  the  ocean,  prevailing  direction  of  the  wind, 
etc.,  that  it  is  only  over  very  localised  areas  that  this  factor 
can  be  utilised  for  determining  whether  a  water  be  polluted 
or  not;  but  on  Continents  like  North  America,  large  areas 
(whole  States  in  fact)  are  so  slightly  affected  by  these 
conditions  that  the  amount  of  chlorine  may  be  used  for 
ascertaining  and  calculating  approximately  the  amount  of 
pollution.  In  Massachusetts  the  whole  of  the  surface  of 
the  country,  with  the  exception  of  a  very  small  portion, 
is  non-calcareous,  and  the  surface  waters  vary  but  little  in 
composition  if  unpolluted,  the  amount  of  chlorine  decreas- 
ing continuously  from  the  coast  inland.  In  a  report  on  the 
State  water  supplies,  1887-1890,  the  Commissioners  state 
that  "  in  a  general  way  four  families  or  twenty  persons  per 
square  mile  will  add,  on  an  average,  .01  of  a  part  per 
100,000  of  chlorine  to  the  water  flowing  from  this  area, 
and  that  a  much  smaller  population  will  have  the  same 
effect  during  seasons  of  low  flow."  They  therefore  tabulate 
the  ninety  surface  waters  of  the  State  that  are  used  for 
public  drinking  supplies  according  to  whether  the  amount 


SURFACE   WATER  35 

of  chlorine  they  contain  is  in  excess  of  the  normal  or  not. 
In  twenty-six  there  was  no  excess  of  chlorine ;  in  twenty- 
three  the  excess  was  so  slight  that  they  could  not  say  that 
they  were  in  the  least  polluted  by  household  waste.  The 
excess  of  chlorine  in  the  others  indicated  that  they  con- 
tained from  one  to  five  per  cent,  of  water,  containing  as 
much  salt  as  ordinary  sewage.  The  average  composition 
of  the  above  three  groups  is  included  in  the  Table  of 
Analyses,  page  44.  The  other  indications  of  pollution  in 
drinking  waters  from  upland  surfaces  and  other  sources 
will  be  fully  considered  later. 

Surface  water  may  not  only  be  discoloured  by  draining 
from  peat-clothed  rocks,  but  may  also  be  turbid,  especially 
after  rain.  When  stored  in  reservoirs,  it  occasionally, 
especially  in  the  late  summer  and  autumn,  acquires  a 
disagreeable  odour  and  taste,  from  the  presence  of  algae 
and  other  low  forms  of  vegetable  life.  The  Massachusetts 
Commissioners  found  that  polluted  waters  were  most 
frequently  so  affected,  and  especially  if  stored  in  shallow 
ponds,  lakes,  or  reservoirs.  Careful  filtration  is  always 
advisable,  to  keep  back  the  organisms  which  otherwise  will 
get  into  the  mains  and  render  the  water,  at  times,  un- 
sightly. Pure  water  in  deep  lakes  and  reservoirs,  though 
by  no  means  exempt,  rarely  acquires  bad  tastes  or  odours. 

Pools  are  collections  of  water  of  limited  extent  in  the 
hollows  of  the  rocks  in  hilly  districts,  and  the  water  may 
have  the  ordinary  character  of  surface  water  from  the 
particular  formation.  Usually,  however,  they  contain 
accumulations  of  dead  and  decaying  vegetable  matters, 
which  render  them  impure.  Ponds  are  usually  artificial 
reservoirs  formed  by  making  an  excavation  in  the  imper- 
vious subsoil,  or  by  lining  with  some  impervious  material, 
such  as  clay,  a  cavity  made  in  the  pervious  superficial 
stratum,  and  storing  water  which  has  drained  from  the 
ground  around.  Such  waters  are  rarely  fit  for  domestic 
use,  not  only  on  account  <^  the  vegetable  matters  contained 


36  WATER  SUPPLIES 

therein,  but  on  account  of  their  liability  to  pollution  by 
cattle,  by  manure  on  the  ground  within  their  drainage  area, 
etc.  Being  shallow,  the  whole  mass  of  water  may  be  frozen 
during  a  severe  and  continued  frost,  and  any  contained  fish 
will  perish ;  afterwards  when  the  ice  melts  these  will 
decompose  and  foul  the  water.  Several  instances  of  this 
kind  have  come  under  my  notice  in  districts  where  the 
inhabitants  depend  upon  ponds  for  their  supply  of  water. 

Suspended  matters  in  surface  waters  may  be  removed 
by  continued  storage  in  large  reservoirs  or  lakes,  when 
time  is  given  for  the  whole  to  subside,  or  by  filtration 
through  sand,  which,  however,  is  troublesome  and  somewhat 
expensive.  The  Massachusetts  Commissioners  point  out 
"  that  when  water  is  taken  from  the  ground  near  streams 
and  lakes  it  is  often  to  a  large  extent  surface  water  so 
thoroughly  filtered  that  it  cannot  be  distinguished  from 
the  natural  ground  water.  This  method  of  purification  by 
natural  filtration  is  an  excellent  one  to  adopt  where  there 
is  a  sufficient  area  of  porous  ground  adjoining  the  surface 
water  source." 

The  advantages  of  converting  lakes  into  reservoirs  for 
storing  water,  over  the  construction  of  artificial  reservoirs, 
are  so  great  that  several  towns  have  already  adopted  this 
plan.  Glasgow  is  supplied  with  water  from  Loch  Katrine ; 
Liverpool,  and  several  other  towns,  from  Lake  Vyrnwy  in 
Wales;  and  Manchester  from  Thirlmere  in  Cumberland. 
As  an  example  of  a  smaller  town  Aberystwith  in  North 
Wales  may  be  quoted ;  it  derives  its  supply  of  water  from 
that  portion  of  the  rainfall  on  Plynlimmon  which  runs 
into  the  Llyn  Llygad  E-heidol  Lake.  The  following 
account  is  taken  in  part  from  evidence  given  at  an 
inquiry  held  by  the  Local  Government  Board,  and  contains 
many  points  of  interest.  The  inquiry  was  held  to  sanction 
a  loan  of  £16,000  to  carry  out  the  work.  At  the  present 
time  the  town  has  a  resident  population  of  about  15,000, 
and  in  summer  a  considerable  number  of  visitors  reside 


SURFACE  WATER  37 

there.  The  scheme  was  completed  in  1883,  and  the  town 
has  now  an  abundant  supply  of  water  of  unexceptionable 
purity. 

The  source  of  supply  is  the  Llyn  Llygad  Rheidol  Lake, 
situated  on  Mount  Plynlimmon,  16J  miles  from  Aberyst- 
with,  and  about  1,650  feet  above  the  sea.  The  wild  nature 
of  the  country  renders  the  possibility  of  pollution  remote. 
The  area  of  the  lake  is  11 J  acres,  its  greatest  depth  60 
feet,  and  the  available  storage  capacity,  supposing  the  bank 
is  raised,  as  proposed,  1  foot,  and  only  15  feet  of  water  is 
drawn  off,  is  nearly  40,000,000  gallons.  This  is  equivalent 
to  eighty  days'  supply  for  a  population  of  25,000  at  20 
gallons  per  head  (that  is,  for  about  twice  the  present 
population  (1892),  summer  visitors  included).  This  would 
be  if  no  rain  were  to  fall  on  the  mountain  for  that  length 
of  time — a  supposition  hardly  ever  likely  to  be  realised. 
Plynlimmon  rises  about  2,500  feet  above  the  sea,  and  is  the 
highest  peak  in  this  part  of  Wales.  The  warm  winds  from 
the  south-west  and  west,  coming  laden  with  moisture, 
impinge  on  the  mountain,  and  their  temperature  being 
suddenly  reduced,  copious  falls  of  dew  and  rain  take  place. 
The  lake  is  actually  fed  with  rain  that  falls  on  the  very 
summit  of  Plynlimmon,  and  it  would  only  be  in  a  most 
extraordinary  season  of  drought  that  no  rain  would  fall  for 
more  than  2^  months.  The  area  draining  into  the  lake  is 
133  acres.  The  actual  rainfall  is  unknown,  but  the  late  Mr. 
Symons  (the  first  authority  on  the  subject)  put  it  at  over  75 
inches.  At  Nantiago  Lead  Mine,  800  or  more  feet  below 
Plynlimmon,  it  was  92  inches  in  1878,  so  that  it  may  be  120 
inches  or  even  more  at  the  summit  of  the  mountain.  The 
very  moderate  rainfall  of  60  inches  only  is  assumed.  Very 
little  would  be  lost  by  evaporation,  the  slopes  of  the 
mountain  being  so  great  that  the  water  runs  off  most 
rapidly;  and  very  little  would  be  lost  by  percolation,  as 
the  mountain  consists  of  Bala  rock,  the  upper  member  of 
the  lower  Silurian  beds,  a  hard  and  more  or  less  imper- 


3$  WATER  SUPPLIES 

meable  formation.  If,  then,  60  inches  only  be  taken  as 
the  available  rainfall  over  133  acres,  the  quantity  flowing 
into  the  lake  would  be  over  180,000,000  gallons,  very 
nearly  a  year's  supply  at  500,000  gallons  daily.  If  the 
available  rainfall  be  100  inches  per  annum  (as  indicated 
by  gaugings  of  the  outflow  from  the  lake),  the  supply  would 
be  300,000,000  gallons  yearly.  The  water  is  carried  from 
the  lake  to  Aberystwith  in  an  iron  main  8  inches  in 
diameter.  Such  a  main,  with  ,the>  minimum  gradient 
obtainable  for  it,  will  deliver  more  than  half  a  million 
gallons  daily.  The  water,  before  being  distributed  in  the 
town,  is  discharged  into  a  service  reservoir,  two-thirds  of 
a  mile  from  the  town  and  130  feet  above  the  highest 
building  in  the  place.  The  general  pressure  throughout 
the  town  is  equal  to  a  head  of  200  feet.  The  capacity  of 
the  reservoir  is  1,000,000  gallons.  From  the  service 
reservoir  the  water  is  distributed  to  the  town  by  a  10-inch 
main.  The  following  is  an  abstract  of  the  estimate  :  — 

Cast-iron  pipes,  34,117  cwts.,  at  5s.  per  cwt.  .  £8,529  5  0 

10-inch  main  from  service  reservoir,  2,338  cwts.  584  10  0 
Excavating  trenches  for  pipes,  and  refilling 

28,804  lineal  yards  at   prices  varying  from 

2s.  in  rock  to  6d.  in  soft  soil  per  yard         .  1,514     8  7 

Laying  pipes  and  jointing  them         .         .         .  1,214     0  8 

Extra  for  junctions  and  special  pipes         .         .  110    0  0 

Carriage  of  pipes         .         .         .         .         .         .  1,055  14  0 

Sluice  valves,  flushing  valves,  air  cocks,  etc.      .  188     9  0 

Posts  to  indicate  line  of  main    .         .         .         .  25    0  0 

Pressure-reducing  tanks  or  break  valves,  and 

fixing  ditto 217  10  0 

Works  at  the  lake  for  drawing  off  the  water  .  185  0  0 

Service  reservoir,  with  valves,  pipes,  etc.,  complete  2,019  11  6 
Contingencies,  law  charges,  and  engineering  at 

7i  per  cent 1,173     4  6 


Total        .         .         .  £16,816  13     3 


The    works    were    duly    executed,    but    the    estimate    was 
exceeded  by  about  £1,000,  a  detour  with  the  water  main 


SURFACE  WATER  39 

having  to  be  made  on  account  of  the  peaty  nature  of  the 
ground.  It  will  be  noted  that  no  land  had  to  be  purchased, 
and  that  no  compensation  water  had  to  be  provided,  both 
important  matters  for  consideration  when  a  public  water 
supply  is  being  provided. 

At  the  Congress  of  the  British  Institute  of  Public  Health 
held  in  1893,  in  Edinburgh,  the  engineer  to  the  City 
Waterworks  gave  a  description  of  the  Loch  Katrine  Water- 
works supplying  Glasgow.  The  paper  contains  much  that 
is  interesting,  and  to  it  I  am  indebted  for  many  of  the 
following  particulars.  When  the  scheme  was  first  pro- 
pounded, Glasgow  had  a  population  of  350,000,  and  it  was 
estimated  that  it  would  increase  to  760,000  in  1900,  and 
that  the  consumption  of  water  would  then  be  30,000,000 
gallons  per  day.  The  works  were  estimated  to  bring 
50,000,000  gallons  per  day.  However,  both  these  estimates 
have  proved  erroneous,  since  the  population  now  (1898) 
being  supplied  with  water  is  1,000,000,  and  the  con- 
sumption of  water  has  risen  from  40  to  54  gallons  per  head, 
so  that  54,000,000  gallons  are  now  used  every  day.  The 
increased  quantity  used  is  attributed  to  several  factors  : 
the  introduction  of  baths  into  the  houses  of  the  well-to-do 
working  classes ;  the  compulsory  fitting  up  of  water  closets 
in  even  the  smallest  class  of  houses;  the  increase  of  public 
urinals,  watering-troughs  for  cattle,  drinking  and  orna- 
mental fountains;  the  introduction  of  several  large  public 
swimming  baths.  Loch  Katrine  is  368  feet  above  the  sea. 
The  area  of  the  loch  is  4|  square  miles,  and  its  drainage 
area  36£  square  miles.  By  means  of  a  small  masonry 
dam  at  the  outlet  the  loch  has  been  raised  four 
feet  above  the  old  summer  level,  and  can  be  drawn 
down  3  feet  below  that  level.  In  this  range  of  7 
feet  there  is  comprised  a  storage  of  5,623,000,000 
gallons,  or  102  days'  supply.  The  surrounding  hills 
rise  to  a  height  of  from  2,300  feet  to  nearly  3,000 
feet;  and  as  a  result  of  this  and  the  proximity  of  the 


40  WATER  SUPPLIES 

district  to  the  west  coast,  which  first  receives  the  moist 
south-west  winds  of  the  Atlantic,  the  rainfall  is  very  large. 
At  Glengyle,  at  the  top  of  the  loch,  the  fall  is  frequently 
over  100  inches  per  annum,  and  the  driest  year  during  the 
last  40  years  (1880)  yielded  69  inches.  The  loch  is  so  deep 
that  the  water  never  freezes  except  in  shallow  and  sheltered 
bays.  Temperature  observations  made  in  1885  and  1886 
show  that  the  water  reached  its  lowest  temperature  of 
38.7°  F.  near  the  bottom,  in  March,  whilst  at  the  top  it 
was  38.1°,  and  that  during  the  rest  of  the  year  the  surface 
water*  was  warmer  than  the  deep  water.  Geologically  the 
district  round  the  lake  consists  of  metamorphosed  mica 
schist  of  the  lower  Silurian  system,  yielding  very  little 
mineral  matter  to  the  rain  falling  upon  it.  The  district  is 
practically  uninhabited,  and  by  a  payment  of  £17,600  to 
the  proprietors  of  the  land  they  have  surrendered  all  rights 
of  feuing  and  of  erecting  houses,  or  of  allowing  additional 
steamers  or  boats  to  ply  on  the  lake.  There  is  much  peat 
on  the  hill  tops,  and  in  times  of  flood  the  streams  are  highly 
coloured,  but  the  relatively  large  size  of  the  loch  and  its 
great  depth  have  an  important  influence  in  removing  the 
peaty  stain.  Analysis  shows  that  it  is  a  very  pure  water, 
exceedingly  soft  (hardness  under  1°).  Notwithstanding 
this  no  case  of  lead-poisoning  through  using  it  has  ever 
been  reported.  A  service  reservoir  8  miles  from  Glasgow 
holds  eleven  days'  supply.  The  aqueduct  was  expected  to 
pass  50,000,000  of  gallons  per  day,  but  the  effect  of  the 
roughness  of  the  channel  in  retarding  the  flow  (friction) 
was  much  more  than  had  been  anticipated,  and  the  flow  is 
only  42,000,000.  The  total  cost  of  the  works,  including  11| 
miles  of  tunnelling,  10 J  miles  open  cutting  and  bridges, 
13|  miles. cast-iron  syphon  pipes  across  valleys,  and  piping 
within  distribution  area,  has  been  close  upon  £1,500,000. 
This  also  includes  works  carried  out  at  other  lochs  to 
provide  40,000,000  gallons  of  compensation  water.  Dupli- 
cation of  these  works  is  now  being  carried  out  which,  it  is 


SURFACE  WATER  41 

estimated,  will  allow  of  100,000,000  gallons  of  water  per 
day  being  drawn  from  the  loch  for  the  supply  of  the  city, 
at  an  additional  cost  of  £1,300,000.  The  domestic  water- 
rate,  which  in  1856  was  Is.  2d.  per  £1  of  rental,  has  been 
reduced  to  5d.  per  £1  (1900). 

The  Derwent  Water  Act  (1899)  marks  an  epoch  in  the 
history  of  water  supplies,  dealing  exhaustively  with  the 
whole  of  the  water  available  in  the  Derwent  watershed, 
and  allocating  it  amongst  all  the  districts  having  claims 
thereto.  It  provides  for  a  Water  Board,  consisting  of 
representatives  elected  by  the  Derbyshire  County  Council 
and  by  the  Corporations  of  Derby,  Leicester,  Sheffield  and 
Nottingham.  The  works  which  this  Board  can  carry  out 
will  be  capable  of  affording  a  supply  of  30,000,000  to 
33,000,000  gallons  per  day,  and  the  estimated  expenditure 
of  the  Board  on  the  proposed  works  is  £5,500,000.  The 
supply  is  allocated  as  follows:  — 

For  the  use  of  the  districts  within  the  County 

of  Derby 5  million  galls,  per  day. 

Derby  Corporation 7         „          ,,  ,, 

Leicester      „          .         .         .        .         .         .  10        „          „  „ 

Nottingham  Corporation        .         ...     4         „          „  „ 

Sheffield  „  .     7 

This  scheme  will  afford  a  supply  of  6,000,000  gallons  of 
water  per  day  per  million  of  money  expended.  A  scheme 
for  supplying  Birmingham  from  the  Elan  and  Claerwen 
watersheds,  now  approaching  completion,  is  estimated  to 
give  10,000,000  gallons  per  day  for  the  same  sum,  but  the 
collectable  rainfall  in  the  Welsh  valleys  is  40  per  cent, 
more  than  in  the  Derwent  Valley. 


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.     >     S     CS        .                                         .03 

GEOLOGICAL  FORMATION. 

1.  Igneous  Rocks  
2.  Metamorpllic,  Cambrian,  Silurian,  and  De 
3.  Calcareous  portion  of  Silurian  and  Devonif 
4.  Yoredale  and  Millstone  grits,  and  non-c 
Coal  Measures  .... 
5.  Calcareous  portion  of  Coal  Measures 
6.  Mountain  Limestone  . 
7.  Lias,  New  Red  Sandstone,  Conglomerate  a 
stone  
8.  Oolite  (one  sample  only)  . 
9.  Lower  London  Tertiaries  and  Bagshot  Bed 

in  "EVnrr,  nnHiirQ  +  a^  TOT,,} 

2  2    ' 

if 

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CHAPTER    IV. 

SUBSOIL    WATER. 


THE  subsoil  or  stratum  immediately  underlying  the  surface 
soil  may  be  of  a  pervious  or  impervious  character.  If 
pervious  a  considerable  portion  of  the  rain  falling  upon  the 
soil  will  pass  down  into  it,  if  impervious  only  a  relatively 
small  portion  will  percolate,  the  larger  portion  running  off 


FIG.  5. — A,  Pervious  subsoil ;  A',  Portion  saturated  with  water  ; 
B,  Impervious  stratum  ;  (7,  spring. 

as  surface  water.  Where  such  an  impervious  rock  occurs 
covered  only  with  the  spongy  debris  of  vegetation,  saturated 
with  water,  we  have  bogs,  marshes,  and  swamps.  The 
district  will  probably  be  malarial  and  the  water  of  a 
dangerous  character.  Where  a  pervious  subsoil  of  sand, 
gravel,  chalk,  limestone,  sandstone,  or  other  rock  overlies 
an  impervious  rock  such  as  clay,  granite,  hard  limestone, 
etc.,  a  portion  of  nearly  every  rainfall  enters  the  subsoil, 
and  being  held  up  by  the  impervious  layer  below  tends  to 
accumulate.  The  water  thus  held  in  the  interstices  of  the 
rocks  lying  immediately  beneath  the  soil  is  "  subsoil  "  or 
"  ground  "  water.  Where  the  pervious  subsoil  fills  in  a 

(45) 


46  WATER  SUPPLIES 

hollow  in  the  more  impervious  stratum,  as  in  so-called 
pockets  of  gravel,  the  ground  may  become  waterlogged — 
that  is,  completely  saturated  with  water.  If,  however,  at 
any  one  or  more  points  the  edge  of  the  containing  basin  is 
depressed,  water  will  overflow,  forming  a  spring.  Such 
overflow  will  only  take  place  when  the  water  in  the  porous 
rock  has  its  surface  level  raised  above  that  of  the  outlet. 
The  portion  below  this  will  still  remain  stagnant.  Where 
the  porous  subsoil  rests  upon  a  flat  or  sloping  impervious 
substratum,  the  subsoil  water  will  be  constantly  in  motion, 
travelling  towards  the  lowest  point,  where  the  impervious 
rock  outcrops.  There  it  will  either  issue  as  a  spring,  or 


FIG.  6. — A,  Pervious  rock  ;  B,  Subsoil  water ;  C,  Spring  ;  I),  Stream  ; 
E,  Clay  or  other  impervious  stratum. 

act  as  the  invisible  feeder  of  a  stream  or  lake.  "  The  action 
of  the  soil  in  regard  to  water  is  in  reality  of  a  threefold 
nature  :  it  may  transmit  water  as  wine  is  transmitted  by 
a  strainer ;  it  may  imbibe  the  moisture  just  as  ink  is 
soaked  up  by  blotting-paper;  and  it  may  hold  or  be 
saturated  by  water,  as  a  sponge  immersed  in  water  is 
saturated  by  liquid  which  flows  from  it  when  the  sponge 
is  lifted  out.  Thus  we  have  to  distinguish  between  the 
permeability,  the  imbibition,  and  the  saturation  of  a  rock. 
The  amount  of  surface  water  which  percolates  through  the 
soil  depends  upon  the  permeability;  the  amount  retained 
as  moisture  of  the  soil  depends  upon  the  imbibition ;  the 
amount  which  can  be  held  by  the  subsoil  as  ground  water 
depends  upon  the  saturation."  *  Clay  exhibits  in  a  high 

*  Miers  and  Crosskey,  The  Soil  in  relation  to  Health. 


SUBSOIL  WATER  47 

degree  the  property  of  imbibing  water,  but  it  is  only  very 
slightly  permeable.  Coarse  gravels,  on  the  other  hand,  are 
exceedingly  permeable,  but  imbibe  little,  and  have  little 
storage  capacity.  The  coarser  the  grain  of  any  rock,  the 
more  freely  will  water  traverse  it,  and  the  springs  which  it 
feeds  will  be  more  quickly  affected  by  the  rainfall.  The 
water  which  penetrates  the  subsoil  will  either  eventually 
flow  out  as  springs  (which  will  become  dry  unless  the  rain 
falls  with  sufficient  frequency  to  keep  up  the  supply  of 
ground  water),  or  if,  from  the  contour  of  the  impervious 
stratum  below,  the  springs  and  outcrop  are  not  at  the 
lowest  level  of  the  water-bearing  stratum,  a  certain  amount 
of  water  will  always  be  retained,  forming?  as  it  were,  an 
underground  reservoir.  If,  by  pumping  or  otherwise,  water 
be  drawn  from  this  reservoir,  the  outflow  from  the  outcrop 
will  be  decreased  by  the  amount  so  removed,  and  if 
sufficient  be  pumped  the  springs  will  cease  to  flow.  The 
level  of  the  water  in  the  subsoil  varies  in  different  places 
and  in  the  same  place  at  different  times.  Where  the  porous 
stratum  is  of  great  thickness  the  water-level  may  be  at  a 
considerable  depth,  depending  chiefly  upon  the  elevation 
of  the  outcrop.  The  level  also  will  vary  with  the  rainfall, 
rising  when  the  amount  percolating  is  in  excess  of  that 
flowing  from  the  springs,  or  being  artificially  removed  from 
wells,  and  falling  when  the  percolation  is  less  than  the 
outflow.  The  rapidity  with  which  the  rise  and  fall  follow 
the  variations  in  the  rainfall  depends  on  the  permeability 
of  the  subsoil  and  its  depth.  Prestwich  states  that  on  the 
chalk  hills  it  takes  from  four  to  six  months  for  the  rainfall 
to  reach  the  water-level  if  at  a  depth  of  200  to  300  feet. 
On  gravel  and  sand,  with  a  water-level  only  a  few  feet  from 
the  surface,  the  rain  would  be  absorbed  and  percolate  much 
more  rapidly,  but  probably  would  not  affect  the  ground 
water  level  for  many  days.  The  varying  level  of  the  river 
into  which  the  ground  water  is  discharged  will  also  affect 
its  height,  since  when  the  river  is  in  flood  the  ground  water 
will  be  held  back  and  rise,  The  fluctuation  will  be  most 


48  WATER  SUPPLIES 

marked  in  wells  near  the  river,  and  least  in  those  at  a 
distance.  When  the  ground  water  enters  the  sea  even  the 
rise  and  fall  of  the  tide  may  cause  the  height  of  the  water 
to  vary.  The  amount  of  water  which  can  be  retained  in  a 
rock  varies  considerably.  Chalk  and  sand  can  hold  about 
one-third  their  bulk  of  water ;  oolite  one-fifth ;  magnesian 
limestone  one-fourth ;  compact  sandstone  and  pebble  beds 
one-eighth  ;  granite  one-fortieth.  Expressed  in  other  words, 
one  cubic  yard  of  chalk  or  sand  saturated  with  water  would 
contain  from  50  to  60  gallons  of  water,  and  an  area  of  one 
acre  three  feet  thick  would  contain  about  260,000  gallons. 

Except  in  depressions  in  the  impervious  substratum 
which  have  no  outlet,  the  water  in  the  subsoil  is  in  constant 
motion,  travelling  towards  the  outflow.  The  rate  of  this 
movement  is  affected  by  the  porosity  of  the  ground,  its 
slope,  freedom  of  outlet,  and  many  other  factors.  At 
Munich  Professor  Pettenkofer  finds  that  the  subsoil  water 
moves  towards  the  Isar  at  a  rate  of  about  15  feet  per  day, 
whilst  at  Berlin  the  movement  towards  the  Spree  is  barely 
perceptible.  At  Buda-Pesth  the  mean  rate,  according  to 
Fodor,  is  174  feet  daily.  The  height  of  the  subsoil  water 
can  be  ascertained  from  the  level  of  the  water  in  the  wells, 
and  its  variations  will  be  indicated  by  the  rise  and  fall  of 
the  water-level.  This  underground  sheet  of  water  may  be 
of  considerable  extent,  but  its  surface  is  not  necessarily  or 
even  usually  horizontal.  It  will  slope  towards  the  outlet, 
not  uniformly,  but  with  a  curved  surface.  When  water  is 
abstracted  at  any  point,  as  from  a  well,  a  portion  of  the 
water  in  the  subsoil  around  drains  into  the  well  to  replace 
that  removed.  The  water-level  for  a  certain  distance  is 
lowered,  the  curved  surface  sloping  less  and  less  as  it  recedes 
from  the  well  (Fig.  13).  The  extent  of  area  drained  will 
vary  with  the  degree  to  which  the  level  of  the  water  in  the 
well  is  depressed,  and  with  the  permeability  of  the  subsoil. 

The  whole  of  the  rain  falling  upon  a  pervious  soil  does 
not  percolate  into  it.  Some  will  run  off  the  surface,  the 
amount  varying  with  the  slope  and  the  nature  of  the 


SUBSOIL  WATER  & 

Surface ;  some  will  be  lost  by  evaporation,  not  only  from  the 
surface  of  the  ground,  but  also  from  the  leaves  of  herbs  and 
trees.     Dr.  Dalton,  at  Manchester,  found  that  only  25  per 
cent,  of  the  rainfall  percolated  to  a  depth  of  3  feet.     Mr. 
Dickenson,  at  King's  Langley,  on  a  grass-covered  gravelly 
loam,    found    that    42.4    per    cent,    reached    that    depth. 
Dr.  Gilbert  and  Mr.   Lawes,  at  Rothamstead,  found  that 
about  37  per  cent,  was  collected  at  a  depth  of  20  inches, 
36  per  cent,  at  40  inches,  and  29  per  cent,  at  60  inches. 
Since  the  loss  by  evaporation  in  the  summer  is  very  great, 
little   or  no  water   may   reach   the   underground   reservoir 
during  the  warmer  months  (April  to  September).     At  Nash 
Mills,    Hemel   Hempstead,    as   an    average    of   twenty-nine 
years'  observations,  the  percolation  in  summer  was  found 
to  be  about  14  per  cent.,  in  winter  61  per  cent.,  during  the 
whole  year  37   per  cent.     The  soil  here  was  chalky.     On 
loose   sands   and  gravel   a   much   larger   proportion   would 
undoubtedly  percolate,  whilst  in  sandstones  probably  only 
about    25    per    cent.,    and    in    limestones    even    a    smaller 
quantity,  would  reach  the  ground  water.     The  most  favour- 
able watershed  is  one  which  is  fairly  level,  sandy  or  gravelly, 
and  having  few  or  no  outlets ;  so  that  nearly  all  the  water 
which  percolates  goes  to  increase  the  underground  supply. 
Where  the  outlets  are  free,   naturally  the  store  of  water 
will  never  be  so  large,  since  it  is  being  constantly  drained 
away. 

Water  is  obtained  from  the  subsoil  by  driving  tubes  or 
by  sinking  wells,  and  these  may  have  galleries  driven  in 
various  directions  to  increase  the  supply.  The  permanent 
yield  of  such  a  well  will  depend  upon  the  area  of  the 
watershed  by  which  the  water  is  collected  and  the  porosity 
of  the  subsoil.  During  dry  weather  the  pumping  opera- 
tions will  lower  the  level  of  the  water  and  provide  space  for 
the  water  which  will  percolate  during  the  wet  season.  To 
obtain  a  permanent  supply  of  a  fixed  quantity  of*  water, 
the  proportion  of  the  rain  falling  upon  the  contributing 

4 


$o  WATER  SUPPLIES 

area  which  can  be  collected  must  be  equal  to  the  quantity 
which  it  is  desired  to  abstract.  If  the  area  of  the  water- 
shed draining  towards  the  proposed  well  be  known,  and  the 
rainfall,  the  depth  of  ground  water  required  to  furnish  a 
given  daily  supply  may  be  approximately  calculated.  Let 
us  assume  that  the  rainfall  records  prove  that  120  days' 
storage  is  required,  and  that  the  amount  of  water  to  be 
raised  daily  is  250,000  gallons,  and  that  the  subsoil  is  sand 
or  gravel.  Such  a  subsoil,  when  saturated,  will  contain 
about  35  per  cent,  of  water;  but  the  whole  of  this  cannot 
be  removed,  only  about  25  per  cent,  will  run  out  when  the 
water-level  is  lowered.  In  order  to  obtain  this  250,000 
gallons  daily  it  will  be  found  by  calculation  that  it  is 
necessary  to  have  storage  equivalent  to  40  acres  of  ground, 
in  which  the  water-level  can  be  lowered  9  feet.  If  a 
superficial  examination  renders  it  probable  that  this  amount 
of  storage  is  available,  a  series  of  tests  must  be  carried  out 
to  confirm  it.  For  this  purpose  a  number  of  test  wells  are 
driven  during  the  dry  season,  and  the  change  produced  by 
long-continued  pumping  observed.  The  depth  to  which 
the  water  surface  is  lowered  at  the  wells  and  at  various 
distances  from  the  wells  will  furnish  the  engineer  with  the 
required  information. 

The  water  from  so-called  shallow  wells  is  subsoil  water, 
and  in  most  villages  and  nearly  all  rural  districts  such  wells 
are  the  chief  source  from  which  water  is  derived.  As  a 
well  only  drains  the  ground  for  a  limited  distance  around, 
where  a  larger  supply  is  required  other  wells  must  be  sunk 
or  galleries  be  driven  in  various  directions  below  the  ground 
water  level.  On  gently  sloping  ground  a  chain  of  wells 
may  be  sunk  and  connected  together.  In  a  valley  through 
which  flows  a  stream  liable  to  pollution,  pure  water  may 
sometimes  be  obtained  by  sinking  wells  along  the  foot  of 
the  hills,  and  so  intercepting  the  ground  water  on  its  way 
to  the  stream.  If  the  bed  of  the  stream  is  formed  of 
permeable  rock,  it  will  be  saturated  with  water  flowing 
slowly  in  the  same  direction  as  the  stream.  Such  a  sub- 


SUBSOIL  WATER  5* 

terranean  river  may  even  convey  more  water  than  the 
visible  stream.  In  the  Thames  valley  it  is  estimated  that 
the  flow  beneath  the  river  considerably  exceeds  that  of 
the  river  itself.  In  seasons  of  drought  the  subterranean 
flow  may  continue  long  after  the  bed  of  the  stream  has 
become  dry,  and  at  such  times  water  may  often  be  obtained 
by  sinking  a  well.  In  galleries  sunk  along  the  course  of 
streams  or  near  the  borders  of  lakes,  where  the  subsoil  is 
pervious,  when  the  level  of  the  water  in  the  galleries  is 
lowered  below  that  of  the  surface  of  the  stream  by  pumping 
or  in  any  other  way,  water  may  flow  from  the  river  or  lake 
into  the  galleries.  Percolation  outwards  through  the  silt 
or  mud  at  the  bottom  of  rivers  and  pools  can  only  take 
place  slowly,  and  no  definite  measurements  have  ever  been 
obtained  of  the  amount.  Where  the  quantity  of  water 
removed  from  the  galleries  does  not  reduce  the  level  below 
that  of  the  free  water  surface,  the  whole  supply  is  derived 
from  the  ground  water  intercepted  on  its  way  to  the 
stream,  and  only  when  the  level  is  reduced  below  the  free 
water  surface  is  the  supply  supplemented  by  backward 
percolation. 

The  quality  of  subsoil  water  will  vary  with  the  character 
of  the  subsoil  and  the  proximity  to  human  habitations.  In 
the  chalk,  lias,  oolite,  sandstone,  and  limestone  districts 
the  water  will  be  hard,  but  the  most  ancient  rocks,  the 
Yoredale  and  millstone  grits,  and  sands  and  gravels 
generally,  yield  soft  water,  if  uncontaminated.  The  living 
earth  has  such  remarkable  powers  of  purification  and  filtra- 
tion, and  the  subsoil  beneath  is  so  effective  a  filter,  that 
natural  ground  water  is  almost  free  from  germs  (often  it  is 
absolutely  free)  and  from  organic  matter.  This  natural  pro- 
cess of  purification  will  be  described  more  fully  in  a  later 
section.  As  usually  derived  from  shallow  wells,  the  subsoil 
water  is  almost  invariably  subject  to  contamination.  The 
Commissioners  appointed  to  examine  the  Domestic  Water 
Supply  of  Great  Britain  reported  that  the  most  dangerous 
water  is  "  shallow  well  water,  when  the  wells  are  situated, 


52  WATER  SUPPLIES 

as   is  usually   the   case,   near   privies,   drains,   or   cesspools. 
Such  water  often  consists  largely  of  the  leakage  and  soakage 
from  receptacles  for  human  excrements ;  but,  notwithstand- 
ing the  presence  of  these  disgusting  and  dangerous  matters, 
it  is  generally  bright,  sparkling,  and  palatable."     In  Table 
IV.  the  highest  and  lowest  results  are  given  of  the  analysis 
of  large  numbers  of  waters  from  various  geological  sources. 
The  majority  of  the  samples,  however,  were  very  impure, 
and  the  lowest  results  only  can  be  considered   typical   of 
pure  water  from  these  sources.     Table  III.  contains  recent 
analyses  of  a  number  of  town  water  supplies  derived  from 
the  subsoil.     It  will  be  observed  that  in  many  cases  nitrates 
(as  indicated  by  the  nitric  nitrogen)   are   present  in  con- 
siderable amount,  and  as  these  salts  are  derived  from  the 
oxidation    of    organic    matter,    such    as    sewage,    manure, 
decaying  vegetables,  etc.,  waters  containing  such  quantities 
of    nitrates     are     often     looked     upon     with     considerable 
suspicion,  and  some  chemists,  relying  upon  their  analytical 
results  alone  absolutely  condemn  these  waters  as  dangerous 
to  health.     Koch,*  comparing  the  processes  of  artificial  and 
natural  filtration,  says  :  "  As  a  rule,  the  soil  is  of  a  material 
much    more    finely    granulated    than    the    comparatively 
coarse-grained  sand  of  the  filter,  and  it  is  fair  to  expect  that 
the  subsoil  water,  after  passing  the  sufficiently  thick  layers 
of  this  finely  granulated  soil,  will  be  either  very  poor  in 
micro-organisms,  or  quite  free  from  them.    This  is  confirmed 
by  the  investigations  of  C.  Fraenkel,  who  has  shown  that 
subsoil  water,  even  in  a  soil  which  has  been  much  and  for  a 
long  period  contaminated,  as  is  the  case  in  Berlin,  is  quite 
free  from  germs.     In  other  places  the  same  results  have 
followed  from  investigations  made  on  this  point.     We  have, 
therefore,  no  reason  to  keep  out  of  consumption  the  subsoil 
water,   which   can   be   found   nearly   everywhere.     On   the 
contrary,   we  cannot  find  a  better-filtered  water  and  one 
more  protected  against  infection.     The  only  difficulty  is  to 

*  Water  Filtration  and  Cholera.     Translated  by  A.  J.  A.  Ball. 


SUBSOIL  WATER  53 

bring  this  perfectly  purified  water  into  consumption 
without  its  being  later  on  again  contaminated  and  infected. 
In  this  respect  great  errors  are  still  most  inexplicably  made 
everywhere."  Wells  as  ordinarily  constructed  yield  polluted 
water  because  no  attempt  is  made  to  keep  out  surface 
water.  Not  only  can  the  pure  water  enter  at  the  bottom  of 
the  well,  but  the  less  perfectly  purified  can  enter  at  the 
sides,  and  the  impure  surface  water  can  gain  access  at  the 
top.  Often  the  wells  are  left  open,  and  so  unprotected 
that  filth  can  be  washed  in  with  every  rainfall,  or,  if 
covered,  the  dome  is  not  water-tight,  nor  the  ground  above 
solid,  nor  of  such  a  character  or  of  such  a  depth  as  to  purify 
the  water  passing  through  it.  Drains  of  most  primitive 
construction  are  often  placed  near  to  carry  away  the  waste 
water  from  the  pump,  but  used  also  for  slop  water  of  all 
kinds.  Waters  from  such  wells  are  notoriously  liable  to 
become  infected,  and  have  often  caused  outbreaks  of 
typhoid  fever  and  cholera.  The  proper  construction  of 
wells  and  the  alteration  of  existing  wells,  so  as  to  render 
them  safe,  are  subjects  of  such  vital  importance  that  they 
will  be  discussed  in  a  special  chapter.  Koch  is  so  convinced 
of  the  absolute  nature  of  the  security  from  the  danger  of 
infection  afforded  by  the  use  of  subsoil  water  properly 
collected  and  stored,  that  he  has  proposed  that  the  Berlin 
waterworks  should  be  so  altered  as  to  supply  the  city  with 
subsoil  water  only.  Buda-Pesth  derives  its  water  supply 
from  the  subsoil  along  the  banks  of  the  Danube,  in  which 
a  chain  of  wells  is  sunk,  and  the  outbreak  of  cholera  in  1893 
was  attributed  to  the  use  of  this  water. 

In  the  State  of  Massachusetts,  forty-two  towns  varying 
in  population  from  2,000  to  25,000  have  public  water 
supplies  taken  from  the  ground.  The  largest  supplies  are 
taken  from  localities  in  the  vicinity  of  large  bodies  or 
streams  of  water.  At  Newton  nearly  2,000,000  gallons  of 
water  are  pumped  daily  from  galleries  extending  for  about 
three-quarters  of  a  mile  along  the  course  of  the  river.  At 
Waltham  a  well  40  feet  in  diameter  is  believed  to  be 


54  WATER  SUPPLIES 

capable  of  yielding  1,500,000  gallons  daily  in  a  dry  season. 
Maiden  and  Revere  may  be  cited  as  examples  of  towns 
supplied  exclusively  with  subsoil  water,  not  supplemented 
by  water  percolating  from  lakes  or  streams.*  "  At  Maiden 
the  amount  pumped  in  1890,  746,446  gallons  daily, 
represented  a  collection  of  9.7  inches  (or  20  per  cent,  of  the 
total  rainfall  of  49  inches)  upon  a  direct  watershed  estimated 
at  1.61  square  miles.  At  Revere  the  pumping  for  the 
year,  465,491  gallons  daily,  represented  a  collection  of  12.5 
inches  (25  per  cent,  of  the  total  rainfall  of  50  inches)  upon 
a  watershed  of  0.78  square  mile."  But  "  it  is  probable  that 
the  amount  which  has  been  pumped  is  more  than  could  be 
pumped  after  one  or  two  years  of  low  rainfall.  At  Revere 
particularly,  experience  has  shown  that  the  storage  capacity 
of  the  ground  is  very  large,  so  that  when  the  water-table 
is  reduced  to  a  very  low  level  during  the  summer,  the 
ground  will  not  fill  before  the  next  summer,  unless  the 
amount  of  rainfall  is  above  the  average." 

Where  it  is  desired  to  obtain  water  from  the  porous 
subsoil,  the  direction  of  the  flow  of  the  ground  water  must 
be  ascertained.  This  will  be  towards  the  springs,  lakes, 
streams,  or  rivers  forming  the  outflow.  The  ground  water 
will  have  its  highest  level  at  the  point  most  distant  from 
the  outflow,  but  most  water  will  be  obtainable  near  the 
outflow,  unless  the  porous  subsoil  rests  in  a  depression 
in  the  impervious  rocks  beneath,  when  most  water  can  be 
procured  where  the  depression  is  greatest.  In  an  inhabited 
district  the  purest  water  will  be  found  on  that  side  which 
is  farthest  from  the  outflow,  since  all  the  impurities  enter- 
ing the  subsoil  will  be  carried  in  the  direction  of  flow  of  the 
underground  water.  For  this  reason  a  pure  water  may 
sometimes  be  found  at  one  side  of  a  house,  when  that  from 
the  opposite  side  is  polluted.  Where  a  patch  of  gravel  is 
bounded  by  streams  on  two  sides,  the  ground  water  will  be 
travelling  in  both  directions,  and  that  at  one  side  may  be 

*  Report  of  State  Board  of  Health,  1890. 


SUBSOIL  WATER 


55 


much  less  impure  than  that  from  the  other.  Thus  in 
Fig.  6,  if  the  village  stand  upon  one  side  of  the  hill,  it  will 
affect  only  the  ground  water  at  that  side,  the  water  on  the 
opposite  side  escaping  contamination.  The  extraordinary 
extent  to  which  the  subsoil  water  can  be  affected  by 
pollution  from  inhabited  houses,  highly  cultivated  land, 
etc.,  is  indicated  by  the  analyses  given  in  Table  IV.  When 
examining  recently  the  water  from  a  gravel  patch  about 
one  square  mile  in  extent,  and  with  a  population  of  about 
1,400  persons  upon  it,  I  found  that  the  water  along  three 
sides  of  the  patch  was  remarkably  constant  and  uni- 
form in  composition,  and  very  free  from  organic  impurity, 
whilst  that  from  the  neighbourhood  of  the  village, 
and  between  the  village  and  the  river,  the  principal 
outflow,  varied  considerably,  and  was  more  or  less 
impure.  In  Table  III.  the  analyses,  Writtle,  Nos.  1,  2, 
and  3,  are  of  waters  taken  from  the  gravel  at  the  three 
first-mentioned  sides;  Nos.  4,  5,  and  6  are  of  water  from 
wells  in  the  village.  The  difference  is  entirely  due  to  the 
soakage  of  slop-water,  sewage  from  defective  drains,  sewers, 
cesspits,  and  cesspools,  into  the  subsoil.  In  some  cases  the 
filth  had  been  very  fully  oxidised  before  reaching  the  well, 
in  others  this  oxidation  was  not  nearly  so  complete.  Such 
waters  are,  of  course,  quite  unfit  for  domestic  use.  Where 
the  surface  soil  has  been  removed,  as  in  the  neighbourhood 
of  inhabited  houses,  the  purifying  influence  of  the  living 
earth  is  lost,  and  where  the  porous  stratum  of  subsoil  is  thin, 
the  purification  by  oxidation  and  filtration  is  but  limited. 
Where  both  these  conditions  occur,  the  subsoil  water  must 
of  necessity  be  very  impure.  Koch's  eulogy  of  the  subsoil 
as  a  source  of  water  supply  must  therefore  be  limited  to 
those  districts  in  which  the  population  is  scattered,  and  the 
subsoil  of  sufficient  depth  to  secure  efficient  filtration  and 
purification.  Where  both  these  conditions  obtain,  the 
ground  may  yield  a  water  of  the  highest  quality,  but  where 
these  conditions  are  not  fulfilled,  there  will  always  be 
impurity  and  risk. 


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CHAPTER    V. 

NATURAL  SPRING  WATERS. 

SPRING  waters  have  always  been  held  in  high  repute  as 
sources  of  domestic  supply,  and  justly  so,  since  springs 
yield  as  a  rule  waters  of  a  high  degree  of  organic  purity. 
As  they  gush  from  the  ground  also  they  can  easily  be 
utilised,  no  form  of  machine  being  necessary  to  raise  the 
water.  Although  usually  so  free  from  organic  matter, 
many  springs  contain  inorganic  constituents  of  such  a 
quality,  or  in  such  quantity,  as  to  confer  upon  them 
medicinal  properties  which  man  has  not  been  slow  to 
utilise.  Numerous  springs  of  this  kind  are  known  which 
have  enjoyed  a  high  reputation  for  their  curative  properties 
from  time  immemorial.  Some  again  yield  water  of  delight- 
ful coldness  throughout  all  seasons  of  the  year,  whilst  others 
yield  warm,  hot,  and  even  boiling  water.  Certain  springs 
also  appear  to  be  perennial,  the  flow  being  constant,  or 
apparently  so,  even  during  periods  of  excessive  drought, 
when  streams  have  ceased  to  flow  and  wells  to  yield.  For 
these  reasons  the  origin  of  springs  had  always  been,  until 
within  a  comparatively  recent  period  a  cause  of  wonder  and 
speculation.  The  facts  brought  to  light  by  the  study  of 
geology  and  hydrology  have,  however,  robbed  them  of  much 
of  their  mystery;  but  the  source  of  certain  constituents 
and  the  cause  of  the  high  temperature  of  the  water  yielded 
by  many  springs  still  give  rise  to  much  discussion.  The 
overflowing  water  varies  in  volume  from  that  of  the  tiniest 
rivulet  to  that  of  a  river  of  considerable  magnitude, 

(59) 


60  WATER  SUPPLIES 

yielding  millions  of  gallons  per  day  as  the  Sorgue  and 
Loiret  in  France,  the  Manifold  and  Hamps  in  Staffordshire, 
and  the  river  Aire  at  Malham  Cove  in  Yorkshire.  The 
pressure  on  the  water  may  only  be  just  sufficient  to  cause 
it  to  overflow  upon  the  ground,  or  it  may  be  so  great,  and 
applied  in  such  a  direction  as  to.  throw  it  vertically 
upwards  for  even  50  or  100  feet  above  the  level  of  the 
surrounding  surface.  Not  only  also  do  springs  arise  in 
valleys  and  depressions  on  the  earth's  surface,  but  some- 
times upon  or  near  the  summits  of  hills  of  considerable 
elevation.  Such  springs,  if  of  any  large  volume,  are  often 
of  great  value,  since  the  water  can  be  conveyed  by  gravita- 
tion to  any  point  at  a  lower  level  where  a  supply  is 
required. 

Springs  are  so  varied  in  character  that  it  is  difficult  to 
classify  them.  According  to  the  temperature  of  the  water, 
we  have  cold  springs,  hot  or  thermal  springs,  and  boiling 
springs  or  geysers.  According  to  the  direction  of  flow, 
we  have  descending  springs  and  ascending  springs;  and 
according  as  they  arise  from  superficial  or  buried  strata, 
we  have  land  springs  and  deep  springs.  The  latter  division  is 
the  most  suitable  for  our  purpose,  though  certain  springs  in 
mountainous  districts  can  scarcely  be  included  under  either 
class.  These  are  springs  originating  from  elevated  lakes, 
or  by  the  melting  of  the  snow  and  ice  of  glaciers.  In  the 
Alps  such  springs  abound.  The  Dauben  See,  a  lake  on  the 
Gemmi,  at  an  elevation  of  7,000  feet,  has  no  visible  outlet ; 
but  about  1,000  feet  lower  upwards  of  fifty  springs  are 
found,  which  appear  to  be  fed  by  the  lake.  By  the  melting 
of  glaciers  resting  on  fissured  rocks,  the  water  traverses  the 
fissures  and  issues  as  springs  in  the  valleys  below.  Land 
springs  proper  occur  where  the  impervious  stratum  sup- 
porting the  pervious  subsoil  outcrops,  providing  the  outcrop 
be  at  a  lower  level  than  that  of  the  subsoil  water.  Where 
the  patch  of  pervious  ground  is  small  in  extent  and  of  little 
depth,  the  springs  arising  therefrom  will  be  "  fleet/'  or 


NATURAL  SPRING   WATERS  61 

Variable,  markedly  affected  by  the  rainfall,  ceasing  to  flow 
during  a  drought  and  flowing  freely  after  heavy  rains.     The 
constancy  of  flow  increases  with  the  extent  of  the  collecting 
surface  and  the  depth  and  permeability  of  the  subsoil.     The 
freedom  of  outlet  also  is  a  factor,  for  if  very  free  the  volume 
of  the  spring  will  be  more  readily  affected  by  the  rainfall 
than  if  the  outlet  be  more  restricted.     Where  the  porous 
subsoil  fills  up  a  hollow  in  the  impervious  rock  beneath, 
the     ground     water     level     may,     during     long  -  continued 
droughts,  sink  below  the  level  of  the  outcrop,  and  it  may 
require  a  series  of  wet  years  to  again  raise  the  level  to  such 
a   height    as    to    cause    the    springs    to    flow.     Many    such 
"  intermittent "    springs    are    known,    e.g.    the    Caterham 
springs  and  the  Hertfordshire  Bourne.     The  latter  appears 
at  intervals  of  four  to  seven  years  (Dr.  Attfield).     Springs 
of  this  character  are  obviously  quite  unsuitable  for  public 
water  supplies,  as  they  are  not  to  be  depended  upon  for  any 
lengthened  period.     Deep  and  ascending  springs  are  usually 
much  more  constant  than  land  and  descending  springs,  since 
they  are  fed  from  subterranean  sources  often  of  vast  extent. 
The   water   also   has   undergone   more   complete   nitration, 
and  any  organic'  matter  originally  contained  in  the  water 
becomes  completely  oxidised,  so  that  such  springs  generally 
yield  water  of  a  high  degree  of  organic  purity.     The  rain 
which  feeds  the  springs  may  fall  upon  the  absorbing  surface 
many    miles    away.     Passing    into    the    pervious    rock,    it 
follows    the    direction    of    this    stratum,    which    first    dips 
downwards   under   some   impervious   formation,    and    later 
outcrops  at  a  lower  level  than  that  of  the  absorbing  surface. 
In  the   chalk   and   other  fissured   rocks   the   water   travels 
chiefly,  if  not  almost  exclusively,  along  the  lines  of  fissure, 
and  where  the  rock  is  soluble  these  fissures  may  become 
enlarged,  until  in  time  caverns  are  formed,  some  of  which 
are  of  great   extent  and  form   subterranean  reservoirs  of 
water.     At     great     depths     water     probably     meets     with 
-carbonic  acid  gas  under  pressure,  which  it  absorbs.     As  the 


62  WATER-SUPPLIES 

temperature  of  the  earth  increases  with  the  distance  from 
the  surface  (on  an  average  the  temperature  increases  1°  C. 
for  every  106  feet  descended),  this  elevated  temperature 
and  the  excess  of  carbonic  acid  increase  greatly  the  solvent 
powers  of  the  water,  and  possibly  explain  the  formation  of 
such  vast  caverns,  and  also  the  greater  richness  of  most  of 
these  springs  in  mineral  constituents.  Water  may  be 
thrown  out,  not  only  at  the  natural  outcrop  of  such  a 
pervious  stratum,  but  by  faults,  or  by  the  filling  up  of 
fissures  with  some  impervious  material  impeding  the 
natural  flow  of  the  water  and  directing  it  upwards  to  the 
surface. 


FIG.  7. 

Artificial  springs  are  formed  wherever  a  communication 
is  made  between  the  surface  of  the  ground  and  the  water 
imprisoned  under  pressure  in  a  pervious  stratum  lying 
between  two  impervious  formations.  Where  the  pressure 
is  sufficiently  great  the  water  overflows.  This  is  the 
principle  of  the  Artesian  well,  which,  however,  will  be 
considered  later  as  a  variety  of  "  deep  "  well.  In  some 
cases,  however,  nature  has  provided  such  a  communication 
between  the  surface  and  the  water  beneath,  by  means  of 
a  fault,  giving  rise  to  a  deep  or  ascending  spring. 

Fig.  7  shows  how  such  a  spring  may  be  formed.  A 
represents  the  superficial  stratum  of  impervious  rock,  C  the 
deep  impervious  formation,  B  the  intermediate  pervious 
bed  collecting  the  rainfall  on  its  exposed  surface  at  an 


NATURAL  SPRING   WATERS  63 

elevation  considerably  above  the  surface  at  the  point  of 
faulting,  D.  It  is  obvious  that  the  depression  of  the  layer 
A  prevents  the  water  stored  in  B  passing  beyond  the  fault, 
and  it  must  therefore  accumulate  until  the  whole  of  that 
portion  of  B  to  the  right  of  the  fault  becomes  saturated, 
unless  some  means  of  escape  is  provided.  The  violence, 
however,  which  produces  a  fault  necessarily  causes  irregu- 
larities in  the  disrupted  surfaces,  and  the  fissures  may 
extend  from  the  surface  down  to  B.  As  the  water-level  in 
the  latter  rises  it  will  fill  these  crevices,  and  finally,  when 
the  level  reached  is  above  that  of  the  ground  at  D,  a  spring 
will  result.  Of  course  the  fissures  above  alluded  to  may 
extend  downward  so  as  to  restore  the  connection  between 
the  two  portions  of  the  pervious  stratum,  in  which  case  no 
spring  will  be  formed,  unless  B  outcrops  at  both  sides  above 
the  level  of  D.  In  the  latter  case  the  spring  will  be  fed 
from  both  sides,  and  therefore  be  of  increased  volume.  If 
the  layer  A  be  of  clay,  or  a  rock  of  similar  nature,  fissures 
would  not  be  formed,  and  the  fault  would  not  therefore 
give  rise  to  a  spring.  The  most  favourable  conditions  exist 
when  A  is  a  hard  rock  and  C  is  of  a  clayey  nature.  The 
two  portions  of  B  will  then  be  completely  disconnected, 
and  the  imprisoned  waters  must  travel  along  the  line  of 
fault  towards  the  surface.  The  springs  at  Clifton  and 
Matlock  are  thus  produced,  and  probably  also  the  equally 
noted  springs  at  Buxton,  Bath,  and  Cheltenham. 

The  amount  of  water  yielded  by  such  springs  depends 
upon  the  amount  of  rainfall  absorbed  by  the  collecting 
surface,  and  is  therefore  proportional  to  the  area  of  such 
surface.  The  character  of  the  water  depends  upon  the 
nature  of  the  rocks  with  which  it  comes  in  contact  in  its 
underground  course.  For  example,  if  it  passes  through 
beds  of  rock  salt,  it  will  take  up  large  quantities  of  that 
substance ;  if  through  beds  of  gypsum,  it  will  contain  much 
sulphate  of  lime. 

Whether  the  quantity  of  water  yielded  by  a  spring  or 


64  WATER  SUPPLIES 

springs  will  be  sufficient  for  the  supply  of  a  town  or  village 
can  only  be  ascertained  by  actual  measurements  of  the  now 
made  at  intervals  through  a  considerable  period,  but  it  may 
be  surmised  from  other  evidence  as  to  the  constancy  of  the 
flow.     A  careful  study  of  the  geology  of  the  district  is  also 
necessary,    and    a    knowledge    of    the    situation,    area,    and 
character    of   the    gathering    ground,    and    of    the    rainfall 
thereupon,  is  also  essential.     It  must  not  be  forgotten  also 
that  where  the  water  chiefly  travels  through  fissures  in  the 
rocks    impurities    may   be    carried    long   distances    without 
undergoing   oxidation   or   other   change   which   will   render 
them  harmless.     In  the  account  of  epidemics  produced  by 
polluted  waters,  examples  will  be  given  of  such  pollution 
and  of  disease  produced  thereby.     The  flow  from  natural 
springs  is  rarely  so  copious  or  so  constant  as  to  render  them 
suitable  sources  from  which  to  supply  towns  of  any  magni- 
tude.    Bristol   originally  derived  the  whole   of  its  supply 
from  springs  at  Chewton  Mendip,  which  yielded  a  minimum 
of  2,000,000  gallons  of  water  a  day  for  a  long  period.     The 
fluctuations  increased,  and  at  length  became  so  serious  that 
the   supply   had   to   be   supplemented   from   other   sources. 
Deep  springs  are  obviously  preferable  to  land  springs,  both 
on  account  of  their  greater  constancy  and  lesser  liability 
to   pollution.     The    water   also   is   usually   more    brilliant, 
sparkling,    and   palatable,    and    is   generally   preferred    for 
domestic  purposes,  unless  the  hardness  is  excessive,  to  water 
from    any    other    source.     Amongst    rural    communities    a 
preference  is  usually  shown  for  natural  springs  with  natural 
surroundings,    and    objections    are    often    raised    to    any 
works    of    an    artificial    character    being    carried    out    for 
protecting   the   water,    or   for   doing   anything   more   than 
is    absolutely    necessary    to    enable    vessels    to    be    filled. 
Where    a    community    is    to    be    supplied,    a    reservoir    is 
necessary,    but   the   capacity   need    rarely    exceed    that   of 
twenty-four    hours'    supply.     A    larger    reservoir    is    only 
required  when  the  flow  at  certain  periods  is  in  excess  of 


NATURAL  SPRING  WATERS  65 

the  demand,  whilst  at  other  periods  it  is  insufficient  to  meet 
all  requirements.  The  amount  of  storage  necessary  to  obtain 
a  constant  and  ample  supply  must  be  determined  from  a 
consideration  of  all  the  circumstances  affecting  the 
particular  case. 

Springs  can  often  be  utilised  very  economically  for 
supplying  mansions  and  small  villages  with  water,  even 
when  the  latter  are  at  a  greater  elevation  than  the  former, 
providing  the  flow  be  sufficient  to  work  a  ram,  turbine,  or 
other  similar  form  of  pumping-engine.  As  only  a  small 
proportion  of  the  water  is  lifted  by  ;the  fall  of  the 
remainder,  this  surplus  water  will  be  available  for  supply- 
ing houses  at  a  lower  level  than  that  of  the  overflow  from 
the  ram  or  turbine.  In  this  way  the  water  yielded  by  a 
spring  on  the  side  of  a  hill  may  be  utilised  for  supplying 
water  to  the  inhabitants  on  the  hill  above  as  well  as  to 
those  in  the  valley  beneath. 

The  following  quotations  from  a  report  by  W.  Whitaker, 
F.R.S.,  on  the  "  Best  Source  for  a  Water  Supply  to  the 
Town  of  King's  Lynn,"  contain  many  points  of  interest, 
since  they  bear  upon  a  number  of  questions  which  have  to 
be  considered  when  a  scheme  for  supplying  a  town  with 
water  is  being  discussed  (King's  Lynn  is  a  town  at  the 
mouth  of  the  Wash,  with  a  population  of  18,265)  : — "  Lynn 
is  one  of  those  towns  which  cannot  get  its  water  supply 
within  its  own  borders.  A  thick  bed  of  clay  underlies  the 
marsh-silt  that  forms  the  surface,  not  only  of  the  town 
itself,  but  also  in  the  greater  part  of  the  neighbourhood, 
where  this  (and  other  alluvial  beds)  have  a  wide  spread 
along  the  main  valley,  with  comparatively  narrow  inlets 
up  the  tributary  valleys. 

"  These  clays  have  been  proved,  by  a  boring  in  the 
northern  part  of  the  town,  to  go  down  to  a  depth  of  about 
680  feet,  and  then,  without  reaching  the  bottom,  leaving  it 
uncertain  how  much  deeper  clay  may  go.  Now  if  a  bed 
usually  of  a  water-bearing  character  should  occur  at  some 

5 


66  WATER  SUPPLIES 

little  further  depth,  it  is  doubtful  whether  a  large  supply 
would  be  got,  at  all  events  by  boring,  for  it  is  often  found 
that  a  thick  mass  of  overlying  beds  tends  to  close  the 
fissures,  etc.,  in  underlying  beds  that,  nearer  the  surface, 
are  quite  permeable.  It  can  readily  be  understood  that 
the  weight  of  a  mass  of  clay  some  700  feet  is  very 
great,  and  is  likely  to  have  an  effect  on  any  limestone  or 
sand  beneath. 

"  Clearly,  therefore,  it  is  needless  to  consider  the  question 
of  boring  for  deep-seated  water  in  the  town.  Very  small 
quantities  of  water  might  possibly  be  got,  from  occasional 
and  local  sandy  beds  in  the  clays;  but  these  would  be 
useless  for  a  public  supply. 

"  Having  then  to  go  outside  the  municipal  boundary,  it 
is  natural  to  consider,  firstly,  the  nearest  source  of  supply. 
This  is  the  lower  greensand  (as  it  is  somewhat  unfortunately 
called,  green  being  generally  an  exceptional  colour  in  it), 
a  formation  which  in  this  part  of  the  country  consists  of 
variously-coloured  sand,  sometimes  cemented  (by  iron  oxide) 
into  the  ferruginous  stone  known  as  carstone,  and  occasion- 
ally with  a  thin  bed  of  clay  in  the  middle  part. 

"  It  has  a  fairly  broad  outcrop  (to  over  five  miles) 
eastward  of  Lynn ;  but  this  is  much  indented  by  alluvial 
deposits  up  the  valley-bottoms,  and  there  are  also  many 
cappings  of  drift  clays  over  the  higher  parts  and  down 
some  of  the  slopes,  even  to  their  bases.  Nevertheless,  the 
formation  being  for  the  most  part  highly  permeable,  much 
water  must  sink  into  it. 

"  The  underlying  Kimmeridge  clay  crops  out  in  places  on 
the  west,  by  the  border  of  the  alluvial  lands,  the  gentle  dip 
of  the  beds  being  easterly;  but  there  are  no  powerful 
springs,  and  consequently,  to  get  a  large  supply  of  water 
from  the  lower  greensand,  it  would  not  do  to  sink  near 
Lynn — that  is,  toward  the  boundary  of  the  formation — 
but  wells  would  have  to  be  made  a  good  way  to  the  east, 
so  as  to  command  the  underground  flow  of  water  from  a 
large  area." 


.      NATURAL  SPRING   WATERS  67 

Dr.  Whitaker  then  expresses  doubt  as  to  whether  one  or 
even  two  wells  would  yield  a  sufficient  supply,  as  in  sands 
underground  galleries  cannot  be  cut,  as  in  limestones,  chalk, 
etc.  Wells  sunk  in  sand  also  often  get  silted  up  and  then 
require  clearing  out.  The  lower  greensand  is  usually  ferru- 
ginous, and  does  not  therefore  yield  a  w  Q,r  of  high  quality. 
Passing  on  to  the  chalk  formation  and  water  obtainable 
therefrom,  Dr.  Whitaker  says  :  — 

"  Much  of  the  water  falling  on  the  chalk  sinks  into  it, 
and  of  this  a  part  finds  its  way  downward,  until  at  some 
depth  the  chalk  is  saturated  and  can  hold  no  more.  The 
level  of  saturation  varies  roughly  with  that  of  the  ground, 
being  higher  at  the  hills  on  the  east  than  at  the  slope 
toward  the  outcrop  of  the  underlying  gault;  the  reason  of 
the  difference  of  level  being  the  frictional  resistance  to  the 
flow  of  the  water  through  the  chalk.  The  underground 
water-slope  in  the  chalk  of  the  immediate  neighbourhood 
being  westward,  the  springs  are  therefore  merely  the 
natural  outflow  of  the  water-charged  chalk,  the  water 
finding  its  way  out  at  the  lowest  available  places,  the 
slowness  of  percolation  through  the  rock  making  the  springs 
constant,  though  of  course  varying  in  amount,  instead  of 
their  being  very  great  at  one  time  (after  heavy  rain)  and 
dry  at  another,  as  would  be  the  case  if  the  water  flowed 
through  quickly. 

"  The  water  of  these  springs  is,  by  nature,  of  the  best 
quality ;  its  only  defect  can  be  hardness,  and  this  can  be 
got  rid  of  to  any  reasonable  extent,  if  needful ;  but  alas ! 
nature  has  not  been  left  alone ;  man  has  changed  the  state 
of  things,  and  not  for  the  better !  Of  the  three  chief 
sources,  two  have  been  polluted  in  a  most  unlucky  way 
(one  by  a  churchyard,  and  the  other  by  the  filth  of  a 
farmyard). 

"  The  intermediate  spring  at  Sow's  Head  is  away  from 
all  buildings.  I  agree  with  Mr.  Silcock  (the  Borough 
Engineer)  that  it  is  to  the  chalk  that  Lynn  should  go  for 
its  water  supply. 


68  WATER  SUPPLIES 

"  Of  the  two  schemes  that  he  has  brought  before  you  to 
get  this  water,  I  must  own  to  a  partiality  for  the  bigger 
one,  for  getting  the  water  by  means  of  a  well  and  galleries, 
somewhere  near  and  above  Well  Hall,  which  would  inter- 
cept the  water  on  its  way  to  the  spring,  and  for  pumping  it 
to  a  reservoir  at  the  brow  of  the  hill,  about  midway  to 
Lynn,  which  certainly  seems  to  be  about  the  best  site  for 
a  reservoir,  there  being  a  mass  of  boulder  clay  over  the  top 
of  the  hill. 

"  As,  however,  there  seems  to  be  no  likelihood  of  large 
increase  in  the  population  of  Lynn,  the  question  of  cost 
must  lead  one  to  look  favourably  on  the  other  scheme,  for 
taking  water  by  gravitation  from  the  Sow's  Head  Spring, 
after  opening  it  out. 

"  I  have  no  doubt  that  the  work  of  cutting  back  and 
opening  out  that  spring  would  result  in  a  goodly  increase 
of  the  outflow;  but  unfortunately  we  have  no  means  of 
saying  how  large  that  increase  would  be,  and  so  it  would 
hardly  do  to  adopt  that  scheme  absolutely  without  some 
further  knowledge.  I  think  therefore  that  Mr.  Silcock  has 
wisely  asked  that  some  preliminary  work  should  be  done, 
at  no  great  cost,  to  try  the  power  of  that  spring.  Of  course 
with  a  spring  supply  you  can  only  take  what  the  spring 
gives  you,  whereas  in  pumping  from  a  well  you  draw  in 
water  from  around,  creating  an  artificial  inflow." 

Excellent  examples  of  the  utilisation  of  natural  springs 
for  the  supply  of  water  to  a  number  of  small  villages  are 
the  works  recently  carried  out  in  the  Chelmsford  Rural 
Sanitary  District  by  the  Authorities'  Surveyor,  Mr.  I.  C. 
Smith,  and  in  the  adjoining  Rural  District  of  Maldon  by 
Mr.  H.  G.  Keywood,  Surveyor  and  Engineer.  These  works 
are  described  in  a  later  section. 

In  the  Massachusetts  Report  on  Water  Supplies  little 
reference  is  made  to  springs,  since  apparently  no  town  is 
supplied  from  such  a  source.  In  the  1891  Report,  however, 
it  is  stated  that  large  quantities  of  spring  water  are  sold 


NATURAL  SPRING  WATERS  69 

throughout  the  state,  "  particularly  in  cities  and  towns 
where  the  regular  water  supply  is  thought  to  be  unsatisfac- 
tory, or  where  the  water,  as  is  not  infrequently  the  case 
with  surface  water  supplies  in  the  summer  time,  has  an  un- 
pleasant taste  and  odour."  "  There  is  also  a  large  amount 
consumed  in  bottled  form,  as  soda  water  and  other  effer- 
vescing drinks."  Waters  were  examined  from  forty-five 
springs,  and  most  of  them  found  to  be  of  the  highest  purity. 
Even  those  samples  taken  from  populous  districts  and  near 
sources  of  pollution  showed  that  a  high  degree  of  purifica- 
tion had  been  effected  by  filtration  through  the  ground. 

The  character  of  spring  water  depends  chiefly  upon  its 
geological  source.  The  water  from  a  deep  spring  will 
naturally  be  characteristic  of  the  stratum  in  which  it  is 
stored  underground,  and  be  little  if  at  all  affected  by  the 
more  superficial  formations  through  which  it  merely  passes 
on  its  way  to  the  surface.  Bearing  this  in  mind,  the 
quality  of  the  water  obtainable  from  springs  arising  in 
various  geological  strata  may  be  described  in  very  few 
words.  In  all  cases  it  is  assumed  that  the  water  is  free 
from  pollution. 

1.  Granite,  Gneiss,  and  Silurian  Rocks. — Usually  excellent 

in  every  way,  their  purity  and  softness  rendering  them 
admirably  adapted  for  drinking,  cooking,  and  washing 
purposes.  The  hardness  rarely  exceeds  7°,  and  is 
usually  much  less. 

2.  Devonian  Rocks  and  Old  Red  Sandstones. — Very  whole- 

some and  palatable.  The  hardness  varies  considerably 
(2°  to  21°).  Usually  they  are  fairly  soft,  but  some 
samples  are  too  hard  for  washing  purposes. 

3.  Mountain  Limestone. — Bright,  colourless,  and  very  palat- 

able, but  usually  too  hard  for  washing  purposes.  The 
average  hardness  is  about  14°,  but  it  may  exceed  30°. 
In  some  the  hardness  is  chiefly  "  temporary,"  in  others 
"  permanent/' 


jo  WATER  SUPPLIES 

4.  Yoredale   Rocks,    Millstone    Grit,    and   Goal   Measures. — 

Generally  wholesome.  Average  hardness  about  10°, 
but  varies  from  2°  to  18°  or  more. 

5.  New  Red  Sandstone. — Yields  water  abundantly,  and  of 

great  purity — bright  and  sparkling.  When  not  too 
hard  it  is  excellently  adapted  for  all  domestic  purposes. 
The  "  permanent "  hardness  usually  exceeds  the 
"  temporary/'  and  the  total  hardness  varies  from  6°  to 
24°,  the  average  being  about  13°. 

6.  Lias. — The  water  from  this  formation  is  usually  so  hard 

(the  average  is  over  20°)  that  unless  artificially 
softened  it  is  not  well  adapted  for  domestic  purposes. 
As  the  hardness  is  generally  of  the  ''temporary" 
character,  it  can  easily  be  reduced  by  any  of  the  lime 
processes. 

7.  Oolites. — Springs    abound    on    this    formation,    and    are 

often  of  immense  volume.  The  water  is  excellent  in 
quality,  though  invariably  rather  hard.  The  average 
hardness  is  17°,  the  extremes  about  12°  and  27°.  The 
hardness  is  almost  entirely  "  temporary,"  and  when 
excessive  can  readily  be  removed. 

8.  Greensands,    Upper   and   Lower. — Although    very   palat- 

able and  wholesome,  the  water  furnished  by  these  sands 
varies  much  in  character.  The  hardness  may  be  less 
than  1°  or  upwards  of  25°.  As  a  rule  it  is  chiefly 
temporary. 

9.  Chalk. — The   water   from   chalk   springs   bears   justly    a 

great  reputation  for  purity,  brightness,  and  wholesome- 
ness,  though  often  the  hardness  is  too  great  for  washing 
purposes.  It  varies  from  8°  to  22°,  with  an  average 
of  17°.  Of  course  it  is  almost  entirely  due  to  car- 
bonate of  lime  and  can  be  readily  removed  where 
necessary. 

10.  Gravel  and  Drift. — Va.ries   to   an   astonishing   degree. 

The  Bagshot  gravels  and  sands  usually  furnish  a  soft 
water,  whilst  some  gravels  yield  water  of  excessive 


NATURAL  SPRING   WATERS  71 

hardness.  Land  springs  alone  are  formed  in  these 
superficial  deposits,  and  the  water  generally  contains 
more  or  less  of  the  products  of  the  oxidation  of 
manurial  matters  which  have  been  applied  to  the 
surface. 

According  to  the  Rivers  Pollution  Commissioners,  the 
chalk,  oolite,  lower  greensand,  and  new  red  sandstone  are 
the  best  water-bearing  strata  in  the  kingdom ;  their  water- 
holding  capacity  is  very  great,  and  the  quality  of  the  water 
excellent.  Where  they  dip  below  any  "  impervious  forma- 
tion they  are  still  charged  with  water  and  easily  accessible 
to  the  boring  rod."  The  most  constant  and  largest  springs 
are  derived  from  the  chalk,  oolite,  new  red  sandstone, 
millstone  grit,  and  mountain  limestone.  In  the  two  latter 
formations  the  water  is  contained  chiefly  in  fissures  (this 
is  probably  the  case  also  with  the  chalk),  and  the  flow  from 
the  springs  therefore  is  more  likely  to  be  markedly  affected 
by  prolonged  drought. 


72 


WATER  SUPPLIES 


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NATURAL  SPRING  WATERS 


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CHAPTER    VI. 

DEEP- WELL  WATERS. 

THE  term  "  deep  "  in  reference  to  wells  is  somewhat 
ambiguous,  since  different  writers  attribute  to  it  different 
meanings.  By  some,  any  well  over  50  feet  in  depth  is 
called  "  deep,"  whatever  the  character  of  the  stratum  in 
which  it  is  sunk,  or  the  strata  through  which  it  passes.  By 
others  the  term  is  used  without  any  reference  to  actual 
depth,  but  to  imply  that  the  well  is  sunk  through  some 
impervious  stratum  into  a  water-bearing  formation  lying  be- 
neath. Such  writers  regard  all  wells  as  "  shallow,"  whatever 
their  depth,  if  they  are  sunk  into  and  yield  water  from  a 
superficial  stratum.  Water  in  the  interstices  of  a  rock 
overlaid  by  an  impervious  formation  must  have  travelled 
some  distance  (often  many  miles)  from  the  outcrop  upon 
which  the  rain  furnishing  it  fell;  hence  filtration  and 
oxidation  is  as  a  rule  very  perfect.  But  where  a  pervious 
formation  is  so  thick  that  the  water  level  is  50  feet  below 
the  ground  surface,  it  is  evident  that  in  percolating  to  this 
depth  the  water  will  have  become  so  purified  as  to  approach 
the  subterranean  water  above  referred  to  in  character. 
Such  being  the  case,  it  is  best  to  consider  such  deep 
superficial  wells  as  "  deep."  yDeep  wells  passing  through 
impervious  into  pervious  and  water-bearing  strata  are  best 
designated  as  Artesian,  although  this  name  is  often 
reserved  for  those  deep  wells  from  which  water  actually 
overflows.  The  first  wells  of  this  character  were  probably 
sunk  in  China;  they  were  common  in  the  East  at  a  very 

(74) 


DEEP-WELL  WATERS 


75 


early  period.  Centuries  ago  they  were  also  sunk  in  the 
province  of  Artois  in  France.  One  such  well  there  has 
undoubtedly  yielded  a  continuous  supply  of  water  since  the 
year  1126  A.D.  At  Grenelle  in  this  province  a  large  boring 
was  commenced  in  1835,  and  was  carried  to  a  depth  of 
about  1,800  feet  before  the  water-bearing  sand  was  reached. 
The  water  then  rushed  in  and  rose  some  60  feet  above  the 
surface  of  the  ground,  the  flow  being  nearly  1,000,000 
gallons  per  day.  With  the  imperfect  appliances  of  that 
period,  the  well  took  six  years  to  bore.  Artesium  being 
the  ancient  name  for  Artois,  all  such  wells  have  since  been 


FIG.  8. 


called  Artesian/The  various  kinds  of  deep  well  are 
illustrated  by  the  above  diagram,  Fig.  8. 

The  water-level  in  the  formation  c  being  at  d,  it  is 
evident  that  a  well  sunk  at  A  would  not  pass  through  the 
superficial  impervious  stratum  6,  yet  would  be  deeper  than 
the  well  sunk  at  B,  passing  through  this  formation  to  reach 
the  same  source  of  water.  The  level  of  the  ground  at  C 
being  considerably  below  the  water-level  d,  water  would 
overflow  from  the  well  at  C.  The  latter,  therefore,  is  a 
true  Artesian  well,  or  we  may  call  it  an  overflowing 
Artesian  well  to  distinguish  it  from  B. 

Very   little    consideration    will    render    it    obvious    that 


76  WATER  SUPPLIES 

pervious  strata  which  lie  below  the  sea-level  must  retain 
within  them  all  the  water  absorbed  at  their  outcrop. 
Formations  of  this  character,  with  extensive  exposed 
surfaces,  passing  under  other  more  superficial  strata,  may 
store  enormous  amounts  of  water,  and  if  they  do  not  reach 
too  great  a  depth,  which  is  rarely  the  case,  water  may  be 
obtained  from  them  by  boring  or  sinking  a  well.  The 
greater  the  depth  to  which  the  boring  passes,  the  greater 
the  supply  of  water  obtainable.  Thus  in  Fig.  8,  as  soon  as 
the  water-level  in  c  became  depressed  by  pumping  from 
A,  B,  or  C,  below  the  bottom  of  A,  that  well  would  cease 
to  yield.  If  the  water-level  became  still  more  depressed 
B  also  might  fail,  whilst  C  would  continue  to  furnish  a 
supply.  This  only  applies  when  the  pumping  at  the  lower 
level  is  withdrawing  more  water  than  is  passing  into  the 
outcrop  from  the  rainfall.  When  such  is  not  the  case,  the 
effect  of  one  well  upon  another,  if  some  distance  apart,  will 
be  inappreciable.  If  the  whole  of  the  pervious  stratum  c 
be  not  saturated  with  water,  the  conditions  will  be  different, 
water  will  be  travelling  in  the  direction  from  A  to  C,  either 
towards  the  sea,  some  river,  or  spring  (unless,  as  occasion- 
ally may  occur,  there  be  no  outlet),  and  the  movement  of 
the  water  present  in  the  rock  may  be  looked  upon  as 
analogous  to  that  of  a  subterranean  river,  or  as  that  of 
water  in  a  cistern  supplied  at  the  top  and  being  drawn  off 
at  the  bottom.  According  to  the  cistern  theory,  pumping 
will  reduce  the  level  of  the  water  without  stopping  the 
"  leakage  "  from  the  bottom,  whilst  on  the  river  theory 
pumping  will  chiefly  affect  the  leakage,  since  abstraction  of 
water  from  any  point  in  a  river  must  decrease  the  flow  of 
water  past  that  point.  The  two  views  were  ably  argued 
before  the  Royal  Commission  on  Metropolitan  Water 
Supply,  and  after  hearing  the  evidence  of  Sir  John  Evans 
and  Mr.  Whitaker  in  favour  of  the  "  cistern  "  theory,  and 
of  Baldwin  Latham  in  favour  of  the  "  river  "  theory,  the 
Commissioners  reported  as  follows  :  — 


DEEP-WELL  WATERS  77 

"  We  are  of  opinion  that  the  analogy  of  a  cistern  is 
inaccurate  and  misleading  when  used  in  relation  to  streams 
at  a  considerable  distance  from  the  points  where  pumping 
is  carried  on.  A  waterworks  well  is  itself  a  typical  cistern ; 
the  pumps  are  not  unfrequently  submerged  many  feet,  and 
when  pumping  commences  it  is  the  bottom  water  that  is 
withdrawn,  and  in  consequence  of  losing  its  support  the 
upper  water  is  proportionally  lowered.  .  .  .  But  in  ad- 
dition to  this  vertical  and  horizontal  lowering  (of  the  water 
surface)  in  the  open  well,  there  goes  on  simultaneously  a 
lowering  of  a  different  character  in  the  chalk  around  the 
well. 

"  Immediately  adjoining  and  outside  an  unlined  chalk 
well,  the  water  lowers  pari  passu  with  that  inside,  but  the 
same  horizontal  plane  is  not  continued  outwards.  The 
water  cannot  pass  through  the  crevices  in  the  chalk  to  the 
well  without  a  certain  amount  of  fall  or  slope,  this  being 
necessary  to  overcome  the  friction  of  its  passage.  Hence 
the  surface  of  the  water  in  the  emptying  chalk  rises  from 
the  well  in  all  directions  at  a  gradient  more  or  less  steep, 
in  relation  to  the  openness  or  closeness  of  the  passages. 
These  slopes  will  nowhere  probably  form  a  symmetrical  or 
regular  cone-shaped  depression  having  the  well  as  its  centre, 
but  slopes  at  varying  angles  modified  by  circumstances  are 
undoubtedly  required  if  the  supply  to  a  well  is  to  be 
maintained  whilst  pumping  is  going  on. 

"  It  is  only  necessary  to  follow  out  this  idea  to  a  distance 
of  miles  from  the  well  to  realise  clearly  that  the  cistern 
theory  is  untenable.  In  the  open  well  the  upper  water  is 
supported  directly  by  that  below  it,  and  when  the  support 
is  removed  the  surface  is  immediately  and  vertically 
depressed.  Out  in  the  body  of  the  chalk  the  upper  water 
is  only  partially  supported  by  that  below  it,  and  mainly  by 
the  chalk  in  and  upon  which  it  lies  and  flows;  and  this 
being  so,  the  analogy  of  a  river  is  much  more  apt  and 
accurate  than  that  of  a  cistern.  Mr.  Baldwin  Latham  and 
other  witnesses  were  therefore  more  nearly  right  than  Sir 


78  WATER  SUPPLIES 

John  Evans,  when  they  said  that  pumping  from  a  well 
tapping  an  underground  stream  flowing  in  a  known 
direction  mainly  affected  the  water  below  the  well,  and 
had  little  effect  on  that  above  the  well/' 

The  same  reasoning  applies  not  only  to  the  chalk,  but 
also  to  all  porous  underground  strata  containing  water 
under  similar  conditions. 

But  few  deep  wells  are  sunk  into  the  Devonian  rocks, 
millstone  grit,  coal  measures,  or  magnesiaii  limestone,  the 
probability  of  obtaining  water  therefrom  being  in  most 
cases  very  problematical.  The  new  red  sandstone,  oolites, 
and  chalk  are  the  great  subterranean  water-bearing  strata, 
the  lias,  greensands,  Hastings,  and  Thanet  sands  having 
smaller  outcrops,  and  being  much  thinner,  and  not  so 
certainly  continuous,  yield  much  more  limited  supplies. 
The  new  red  sandstone  is  an  exceedingly  effectual  filtering 
medium,  and  from  the  great  extent  of  this  formation  vast 
quantities  of  the  purest  water  are  stored  in  it,  and  often 
can  be  rendered  available  at  a  comparatively  slight  ex- 
pense. The  oolites,  according  to  the  R.  P.  C.,  "  contain  vast 
volumes  of  magnificent  water  stored  in  their  pores  and 
fissures  .  .  .  and  it  cannot  be  doubted  that  a  considerable 
proportion  of  this  could  be  secured  for  domestic  supply  in 
its  pristine  condition  of  purity  at  a  moderate  cost."  The 
chalk  formation  is  one  of  the  most  absorbent;  therefore  a 
large  proportion  of  the  rainfall  upon  its  outcrop  passes  into 
it  and  becomes  thoroughly  filtered  and  purified.  The 
R.  P.  C.  found  the  deep-well  waters  from  the  chalk  "  almost 
invariably  colourless,  palatable,  and  brilliantly  clear." 
"  The  chalk,"  they  say,  "  constitutes  magnificent  under- 
ground reservoirs,  in  which  vast  volumes  of  water  are  not 
only  rendered  and  kept  pure,  but  stored  and  preserved  at  a 
uniform  temperature  of  about  10°  C.  (50°  F.),  so  as  to  be 
cool  and  refreshing  in  summer,  and  far  removed  from  the 
freezing-point  in  winter.  It  would  probably  be  impossible 
to  devise,  even  regardless  of  expense,  any  artificial  arrange- 
ment for  the  storage  of  water  that  could  secure  more 


,      -     .^r-THE 

I     UNtVE  *  DEEP-WELL  WATERS  79 

x. 

favourable  conditions  than  those  naturally  and  gratuitously 
afforded  by  the  chalk,  and  there  is  reason  to  believe  that  the 
more  this  stratum  is  drawn  upon  for  its  abundant  and  excel- 
lent water  the  better  will  its  qualities  as  a  storage  medium 
become.  Every  1,000,000  gallons  of  water  abstracted  from 
the  chalk  carries  with  it  in  solution,  on  an  average,  1J  tons 
of  chalk,  through  which  it  has  percolated,  and  this  makes 
room  for  an  additional  volume  of  about  110  gallons  of 
water.  The  porosity  and  sponginess  of  the  chalk  must 
therefore  go  on  augmenting,  and  the  yield  from  the  wells 
judiciously  sunk  ought  within  certain  limits  to  increase 
with  their  age."  Strange  as  it  may  appear,  this  does  not 
apply  to  waters  from  the  chalk  in  certain  districts  which, 
instead  of  being  hard,  as  is  usually  the  case,  are  excep- 
tionally soft,  containing  sometimes  not  more  than  two 
grains  of  chalk  in  solution  in  each  gallon.  Such  exceptions 
prove  that  the  underground  sheet  of  water  is  not  continuous. 
As  previously  explained,  this  is  occasioned  chiefly  by  faults 
interrupting  the  continuity  of  the  strata,  and  such  faults 
may  seriously  affect  the  supply  obtainable  from  any 
particular  well.  Besides  such  faults,  various  foldings  and 
irregularities  often  occur,  dividing  and  subdividing  the 
subterranean  reservoir,  cutting  off  more  or  less  completely 
one  compartment  from  another,  and  limiting  the  supply. 
Before  sinking  a  deep  well,  therefore,  many  points  have  to 
be  carefully  considered  if  the  possibilities  of  failure  are  to 
be  reduced  to  a  minimum. 

The  chief  are  :  — 

1.  The  extent  and  character  of  the  absorbing  area  or  out- 
crop, whether  bare  or  covered  with  drift,  whether 
level,  undulating,  or  hilly;  its  elevation  above  the 
district  proposed  to  be  supplied  by  the  wells;  the 
density  of  the  population  upon  it,  or  discharging 
their  sewage  thereon. — Notwithstanding  the  purify*- 
ing  action  of  porous  rock,  it  is  not  desirable  to  have 
a  dense  population  upon  the  outcrop,  as  in  course 


8o  WATER  SUPPLIES 

of  time  the  water  may  become  affected.  Many  wells 
have  had  to  be  closed  for  this  reason.  At  Liverpool, 
for  instance,  several  deep  wells  belonging  to  the 
Corporation  became  polluted  by  the  population  on 
the  collecting  area,  and  had  to  be  abandoned. 
Where  the  subterranean  water  is  chiefly  collected  in 
and  travels  through  fissures  this  danger  is  accentu- 
ated. The  extent  of  the  absorbing  area  is  often 
difficult  to  determine,  as  implicit  reliance  cannot  be 
placed  on  maps.  The  sections  at  the  surface,  by 
which  the  geological  structure  was  determined  at 
the  time  of  the  survey,  are  occasionally  misleading. 

2.  The  average  rainfall  for  a  number  of  years. — This  being 

known,  and  the  nature  of  the  surface  determined,  a 
rough  estimate  of  the  amount  of  water  absorbed  may 
be  formed  (vide  Chap.  XVII.).  But  the  outcrop  may 
receive  the  drainage  of  a  neighbouring  impervious 
area,  or,  on  the  other  hand,  the  contour  or  surface  of 
the  outcrop  may  be  such  as  to  throw  off  an  unusual 
proportion  of  the  rainfall,  or  much  of  that  absorbed 
may  flow  away  from  springs.  The  levels  of  the 
springs  must  be  studied  to  ascertain  the  direction  of 
flow  of  the  underground  water,  and  their  positions 
may  lead  to  important  inferences  with  reference  to 
the  continuity  or  otherwise  of  the  water-bearing 
stratum,  the  presence  of  faults,  Grumblings,  or  other 
irregularities. 

3.  The  continuity  of  the  water-bearing  strata  and  their 

superficial  area  and  thickness. — The  maps  issued  by 
the  Geological  Survey  show  the  position  and  throw 
of  all  known  faults,  but  trial  bores  have  frequently 
to  be  made  to  ascertain  whether  others  exist,  unless 
their  absence  is  proved  by  existing  wells.  The  study 
of  data  obtained  from  recorded  well  sections,  or  by 
the  results  of  trial  bores,  will  give  an  idea  of  the 
thickness  and  extent  of  the  porous  stratum.  The 
thickness  may  vary  considerably.  Thus  the  chalk  at 


DEEP-WELL  WATERS  81 

Norwich  is  nearly  1,200  feet  thick,  in  Wiltshire 
800  feet,  in  Surrey  350  to  400  feet,  in  East  Kent 
800  feet,  at  Harwich  888  feet,  at  Kentish  Town 
640  feet.  The  lower  greensand  which  lies  beneath 
the  chalk  has  a  thickness  of  probably  600  feet  in  the 
Isle  of  Wight,  but  it  rapidly  thins  away  and  appears 
to  be  absent  under  London.  As  an  instance  of  the 
difficulties  met  with  in  determining  the  extent  of  an 
underground  water-bearing  deposit,  and  of  the  un- 
reliability of  maps,  Mr.  Hodson,  C.E.,  states  *  that 
when  investigating  "  an  area  of  lower  greensand, 
which  the  Ordnance  Survey  showed  as  occupying  an 
area  of  about  8|  square  miles,  of  which  the  outflow 
lay  to  the  south-west,  a  careful  examination  proved 
that  a  main  anticlinal  existed  which  brought  up  an 
underground  ridge  of  impervious  Weald  clay,  which, 
although  not  apparent  on  the  surface,  effectively 
divided  the  underground  sheet  of  water,  and  diverted 
to  an  outflow  on  the  south-east  the  water  absorbed 
on  3J  miles  of  the  watershed,  leaving  only  5|  miles 
as  possibly  available.  In  addition  to  this  the 
evidence  afforded  by  the  springs  conclusively  showed 
that  other  smaller  anticlinals  existed,  which  held  up 
the  water  as  in  a  series  of  troughs,  which  made  it 
very  doubtful  whether  more  than  one  square  mile 
could  be  commanded  by  any  particular  well ;  whilst 
to  complete  the  uncertainty,  notwithstanding  the 
most  persistent  efforts,  it  was  impossible  to  discover 
all  the  lower  greensand  area  given  by  the  map,  and  a 
large  district  clearly  marked  as  upper  greensand 
was  just  as  clearly  gault." 

4.  The  selection  of  a  site  for  the  well. — Underground 
water  not  flowing  in  a  well-defined  channel,  there  are 
no  laws  conferring  prescriptive  rights  of  property; 

*  A  paper  on  Underground  Water  Supplies,  communicated  to  the 
Incorporated  Association  of  Municipal  Engineers,  May,  1893, 

6 


82  WATER  SUPPLIES 

hence  if  a  well  be  so  placed  that  its  supply  of  water 
is  affected  by  the  pumping  from  another  well, 
there  is  no  remedy  at  law.  A  site,  therefore,  should 
be  chosen  so  as  to  tap  the  water  at  a  point  where  it 
is  least  likely  to  be  influenced  by  other  wells  (vide 
page  76).  The  multiplication  of  deep  wells  in  and 
around  London  has  lowered  the  water-level  con- 
siderably, and  in  many  parts  of  Essex,  wells  which 
were  sunk  fifty  years  ago,  and  then  overflowed,  only 
yield  water  when  raised  by  pumps.  In  many 
instances,  where  the  wells  had  ceased  to  yield,  the 
deepening  of  the  reservoir  (or  sunk  portion  of  the 
well)  or  the  lengthening  of  the  pump  pipe  has 
restored  the  supply. 

The  advantages  of  underground  water  supplies  wherever 
obtainable,  as  compared  with  impounding  schemes,  are 
that  large  reservoirs  are  not  required,  very  little  land  is 
wanted,  no  compensation  water  has  to  be  provided,  or  water 
rights  acquired  from  neighbouring  landowners,  filter  beds 
are  unnecessary,  and  the  possibility  of  the  water  becoming 
polluted  is  much  less.  Against  these  advantages  must  be 
placed  the  cost  of  pumping ;  but  "  in  these  days  of  modern 
high-class  pumping  machinery,"  Mr.  Hodson  says,  "  the 
additional  cost  is  so  trifling  as  not  to  be  worthy  of  serious 
consideration;  in  fact,  the  expenses  of  pumping  to  a 
moderate  height  with  good  machinery  are  even  less  than 
the  annual  charges  for  interest  and  working  expenses  of 
filter  beds  alone."  These  remarks,  of  course,  apply  only  to 
comparatively  large  centres  of  population.  The  expense  of 
boring  a  well  to  any  considerable  depth  prevents  such 
supplies  being  obtained  for  single  houses  or  small  com- 
munities, except  in  certain  districts  where  no  other  source 
is  available.  The  mode  of  construction,  cost,  etc.,  will  be 
discussed  in  the  section  on  "  Wells  and  Well  Sinking." 

The  distance  within  which  one  deep  well  can  affect 
another  in  a  continuous  stratum  depends  upon  many 


DEEP-WELL  WATERS 


circumstances,  such  as  the  porosity  of  the  rock,  presence  of 
fissures  and  their  direction,  etc.  In  London  there  are  wells 
within  very  few  yards  of  each  other,  the  supplies  from 
which  appear  to  be  unaffected  by  their  contiguity.  On  the 
other  hand  the  Windsor  Well,  210  feet  deep,  belonging  to 
the  Liverpool  Corporation,  is  said  to  have  affected  the 
surrounding  wells  to  a  maximum  distance  of  1|  miles. 
Certain  very  deep  wells  in  Essex  are  found  to  affect  others 
within  a  radius  of  1^  miles. 

In  the  Lea  valley  the  underground  water-level  has  been 
carefully  ascertained.  From  Chadwell  springs  to  Cheshunt 
there  is  a  fall  of  four  feet  per  mile;  from  Cheshunt  to 
Waltham  Abbey  18  feet  per  mile,  and  from  Cheshunt  to 
Hoe  Lane  11  feet  per  mile.  Between  Hoe  Lane  and 
Walthamstow  the  fall  averages  9  feet,  whilst  between  here 
and  the  city  the  fall  varies  from  22  to  32  feet  per  mile. 
The  increased  fall  south  of  Cheshunt  is  doubtless  due  to  the 
pumping  under  London,  which  is  abstracting  more  water 
in  a  given  time  than  can  pass  through  the  chalk,  com- 
pressed as  it  is  by  great  thickness  of  clay  above  it.  The 
effect,  therefore,  of  the  excessive  abstraction  of  water  from 
the  deep  wells  in  London  is  affecting  the  water-level,  or 
plain  of  saturation,  to  a  distance  of  10  or  12  miles  north  of 
the  city. 

The  following  well  sections,  typical  of  those  in  and 
around  London,  are  taken  from  Whitaker's  Geology  of 
London : — 


BANK  OF 

COLD  BATH 

COVENT  GARDEN 

ENGLAND. 

FIELDS. 

MARKET. 

Thick- 
ness. 

Depth. 

Thick- 
ness. 

Depth. 

Thick- 
ness. 

.Depth. 

River   Gravel   and  made 

ground 

26 

26 

24 

24 

25 

25 

London  Clay 

111 

137 

45 

69 

135 

160 

Woolwich    and    Beading 

Beds    . 
Thanet  Sand 

584 
39 

195£ 
234J 

55 

8 

124 
132 

f  100 

260 

Chalk       . 

100 

334£ 

20 

152 

98 

358 

WATER  SUPPLIES 


SOUTHEND  WATER- 
WORKS, ESSEX. 

WALTHAM  CROSS, 
HERTS. 

STREATHAM 
COMMON, 
SURREY. 

Thick- 
ness. 

Depth. 

TS-          "epth. 

Thick- 
ness. 

Depth. 

Surface    Soil 

3 

3  (Gravel) 

13J       13J  (Mould) 

2 

2 

London  Clay 

414 

417 

64£       78 

178 

180 

Sands   . 

181      598 

64      :  142 

195 

285 

Chalk  . 

302      900 

...      '142  + 

285  + 

The  average  depth  of  tube  wells  in  London  is  about  400 
feet,  and  in  most  instances  the  deep-well  pump  has  to  be 
fixed  from  200  to  300  feet  from  the  surface.  Messrs.  Isler 
and  Company,  who  have  bored  many  of  these  wells,  state 
that  the  yield  obtained  varies  from  1,800  to  7,200  gallons 
per  ho-ur  from  single  bores.  No  attempt  appears  to  have 
been  made  to  sink  a  well  of  any  considerable  diameter  into 
the  chalk  under  London.  Doubtless  such  a  well,  with  adits, 
would  yield  water  in  much  larger  quantities  than  the 
bores  now  made.  There  are  great  engineering  difficulties, 
however,  in  sinking  through  the  sands  lying  between  the 
clay  and  the  chalk,  and  driving  adits  at  such  a  depth  would 
be  no  simple  task.  The  East  London  Water  Company, 
however,  have  sunk  such  a  well  at  Barking,  where  the  chalk 
is  not  nearly  so  deep,  and  are  obtaining  some  2,000,000 
gallons  of  water  per  day  therefrom.  I  am  informed  that 
the  pumping  was  at  the  rate  of  5  million  gallons  per  day, 
when  driving  the  adits,  in  order  to*  keep  down  the  water  to 
the  necessary  level. 

At  Bourn,  in  Lincolnshire,  Messrs.  Isler  and  Company 
recently  bored  a  well  for  the  supply  of  the  town  of 
Spalding.  At  a  depth  of  134  feet  in  the  limestone  beds 
of  the  lower  oolite  water  was  reached,  and  rushed  out  of  the 
bore  pipe  above  the  surface  at  the  rate  of  over  200,000 
gallons  per  ;ho<ur,  or  about  5,000,000  gallons  6per  day. 
It  is  probably  the  most  prolific  underground  spring  yet 
tapped  in  England  (Fig.  9). 


DEEP-WELL  WATERS  85 

From  time  to  time  proposals  have  been  made  to  further 
increase    the    supply    of    deep-well    water   for    the    City    of 


FIG.  9. — Overflow  from  an  Artesian  well  recently  bored  at  Bourn,  Lincoln- 
shire, by  Messrs.  C.  Isler  and  Company,  for  the  supply  of  the  town  of 
Spalding. 

London,    and   the   whole   subject   has   recently   been   fully 
investigated  and  reported  upon  by  a  Royal   Commission. 


86  WATER-SUPPLIES 

It  is  calculated  that  40,000,000  gallons  a  day  is  obtainable 
from  wells  in  the  Lea  valley,  or  27,500,000  more  than 
is  at  present  being  pumped;  from  wells  in  the  Kent 
Company's  district  27,500,000  gallons,  or  11,000,000  a  day 
more  than  at  present.  The  data  and  reasoning  upon  which 
such  estimates  are  based  may  be  illustrated  from  that 
portion  of  the  Commissioners'  Report  referring  to  the  Lea 
valley. 

1.  The  area  of  the  collecting  surface  is  estimated  at  422 
square  miles,  a  portion  consisting  of  bare  chalk,  or  chalk 
covered  with  permeables,  the  remainder  of  chalk  covered 
with  partially  or  wholly  impermeable  beds  draining  on  to 
the  chalk. 

2.  The  mean  annual  rainfall   of  a  long  term   over  this 
area  is  26.5  inches,  the  average  of  three  consecutive  dry 
years  is  22.8  inches,  and  the  fall  in  the  driest  year  19  inches. 

3.  In  the  Thames  valley  the  average  annual  evaporation 
is  16  inches,  and  in  the  driest  year  14.     Assuming  the  same 
to   hold    in    the    Lea    watershed,,  the    evaporation    on    an 
average  of  three  consecutive  dry  years  would  be  about  14.8 
inches,  leaving  8  inches  to  run  off  into  the  rivers  or  to 
percolate  into  the  ground.     Of  that  which  gets  into  the 
ground  a  portion  is  returned  to  the  river.     From  measure- 
ments made  as  to  the  yearly  discharge  at   Field's  Weir, 
above  which  the  river  receives  the  whole  of  the  drainage  of 
this  area,  the  mean  discharge  represents  4.6  inches  flowing 
off.     Deducting   this   from   8    inches,    the   amount    left   to 
percolate  is  3.4  inches,  which  would  yield,  from  an  area  of 
422  square  miles,  3,304,000,000  cubic  feet  per  annum,  or 
56,000,000  gallons  per  day.     But  the  whole  of  this  water 
as   it   travels   past   the   wells   down   the   valley   cannot   be 
intercepted. 

"  In  the  driest  of  three  years,  therefore,  especially  if  it 
came  to  the  last  in  the  cycle,  56,000,000  would  clearly  not 
be  obtainable,  probably  not  more  than  47,000,000,  but  we 
believe  that  the  Companies,  after  providing  reasonably  for 


DEEP-WELL  WATERS  87 

all  below  them,  might,  under  the  worst  conditions,  reckon 
on  obtaining  40,000,000  gallons  a  day." 

Professor  Boyd  Dawkins  believes  that  the  body  of  the 
chalk  contains  such  a  store  of  water  that  it  would  equalise 
the  rainfall,  so  that  the  amount  available  even  during 
three  consecutive  dry  years  would  be  little  short  of  that 
obtainable  with  an  average  rainfall.  With  this  opinion  the 
reporters  disagree,  since  they  consider  that  the  only  avail- 
able water  is  in  the  fissures  and  crevices  of  the  chalk,  and 
that  when  these  are  drained  the  water  held  in  the  body  of 
the  chalk  by  capillarity  oozes  out  so  slowly  as  to  be 
practically  useless. 

In  the  subjoined  table  are  given  the  analyses  of  a 
number  of  public  water  supplies  derived  from  deep  wells 
in  various  strata.  With  one  or  two  exceptions  they  are 
quite  recent.  ^^Deep-w ell  water  differs  little  from  spring 
water  from  the  same  geological  source.  [^An  exception, 
however,  occurs  in  certain  districts  where  the  chalk  lies  at 
a  great  depth  beneath  the  London  clay,  and  yields  a  very 
soft  water  containing  carbonate  and  chloride  of  sodium. 
This  is  well  adapted  for  domestic  purposes,  but  not  for  use 
in  high  pressure  boilers,  nor  for  irrigation.  Boilers  in 
which  it  is  used  quickly  leak,  and  the  saline  constituents 
have  a  prejudicial  effect  upon  many  forms  of  plant  life. 

The  utilisation  of  subterranean  water  obtained  from 
bored  wells  is  in  many  of  our  colonies  converting  deserts 
into  fruit  gardens,  and  rendering  habitable  large  extents 
of  country  in  which  life  was  previously  impossible  on 
account  of  the  scarcity  of  water/ vide  Chap.  XVIII.). 


88 


SUPPLIES 


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CHAPTER  VII. 

RIVER  WATER. 

THE  whole  surface  of  any  given  country  can  be  divided  into 
"  catchment  basins,"  each  such  basin  including  an  area  of 
land  surface  draining  into  a  particular  river.  The*  district 
so  drained  is  also  called  the  watershed  of  the  river,  and  it 
may  vary  in  extent  from  a  few  square  miles  to  thousands 
of  square  miles.  The  watershed  of  any  large  river  flowing 
directly  into  the  ocean  may  be  said  to  include  and  be 
greater  than  the  watersheds,  drainage  areas,  or  catchment 
basins  of  all  its  tributaries.  The  actual  point  at  which  a 
river  takes  its  rise  is  often  difficult  to  decide.  If  it 
originates  at  the  natural  outlet  of  a  lake  or  from  a  powerful 
spring,  the  point  at  which  it  comes  into  existence  is  obvious. 
If,  however,  it  is  formed  by  the  meeting  of  the  waters  of 
two  or  more  rivulets  of  tolerably  equal  length  and  flow, 
then  the  claims  of  any  one  of  the  streams  to  be  the  parent 
stream  may  be  disputed.  A  stream  may  arise  from  a 
spring,  and  for  some  short  distance  may  consist  of  pure 
spring  water,  but  its  volume  is  soon  increased  by  surface 
and  subsoil  water,  so  that  all  river  waters  may  be  said  to 
consist  of  mixtures  of  waters  in  varying  proportion  from  all 
three  sources.  As  these  waters  will  also  vary  with  the 
geological  character  of  the  district,  and  the  nature  of  the 
subsoil  and  surface,  it  is  obvious  that  the  waters  of  different 
rivers  will  not  only  differ  from  each  other,  but  that  water 
from  the  same  river  taken  at  different  points,  or  even  from 
the  same  point  at  different  seasons,  may  vary  considerably 

(90) 


RIVER   WATER  Qt 

in  composition.  Where  the  water  of  a  tributary  differs 
much  in  appearance  from  that  of  the  parent  stream,  the 
difference  can  often  be  observed  for  some  distance  below 
the  point  of  entrance  of  the  smaller  stream.  In  some 
instances  the  effect  of  such  admixture  is  very  marked. 
Upon  Axe  Edge  in  Derbyshire  a  highly  calcareous  stream 
joins  a  ferruginous  one.  Before  combining,  both  are  clear ; 
after  mixing,  the  stream  becomes  red  and  turbid,  deposits 
an  ochrey  substance  upon  its  bed,  and  only  again  becomes 
pellucid  after  flowing  a  considerable  distance. 

Unfortunately,  in  all  inhabited  districts  the  rivers  not 
only  receive  the  natural  drainage,  but  are  also  the  ultimate 
receptacles  of  all  the  polluted  waters  (sewage)  artificially 
collected  from  manufactories,  groups  of  houses,  and  from 
towns  within  their  watersheds.  Notwithstanding  the  Rivers 
Pollution  Act,  nearly  every  stream  of  any  size  in  this 
country  is  at  the  present  time  so  befouled ;  the  defilement 
in  many  instances  being  so  great  that  the  rivers  are 
practically  open  sewers.  Where  the  sewage  is  chemically 
treated  before  being  allowed  to  pass  into  the  streams,  most 
of  the  suspended  impurities  are  removed,  and  possibly  a 
portion  of  those  previously  held  in  solution.  If  the  sewage 
be  disposed  of  by  broad  irrigation  or  by  intermittent 
downward  filtration  through  land,  it  is  still  further  purified, 
most  if  not  all  the  organic  matters  being  removed  or 
destroyed  by  oxidation.  From  highly  cultivated  land  also 
a  certain  amount  of  filth  may  reach  the  streams,  especially 
during  heavy  rains,  when  much  of  the  rainfall  not  only 
dissolves  impurities  but  carries  with  it  into  the  river  other 
matters  in  suspension.  This  rapid  inrush  of  water  disturbs 
the  mud  and  deposit  at  the  sides  and  in  the  bed  of  the 
stream,  and  for  a  time  increases  the  rapidity  of  the  flow, 
and  renders  the  water  turbid  and  still  more  impure. 
Rivers  rising  and  flowing  through  very  thinly-populated 
districts  may  yield  water  to  which  no  possible  objection  can 
be  taken,  from  a  hygienic  point  of  view, — water  which 


92  WATER  SUPPLIES 

may  be  admirably  adapted  for  all  domestic  and  other 
purposes,  and  which  it  is  in  the  highest  degree  improbable 
will  ever  act  as  the  carrier  of  the  germs  of  disease.  Many 
rivers,  however,  are  utilised  as  sources  of  public  water 
supplies  which  are  continuously  receiving  sewage  from  towns 
or  villages  at  points  above  the  intake.  The  Thames  is  such 
a  river,  and  the  Royal  Commission  which  recently  inquired 
into  the  water  supply  of  the  Metropolis  reported  that  there 
was  no  evidence  of  the  pollution  causing  any  injury  to  the 
health  of  those  drinking  the  water,  and  even  advocated  the 
increased  utilisation  of  the  Thames  for  the  supply  of  water 
to  the  capital.  The  utilisation  of  rivers  as  water  supplies 
is  so  dependent  upon  the  possibility  of  the  water  being 
purified,  that,  although  the  subject  will  be  discussed  later, 
some  reference  must  be  made  to  it  here.  The  self-purifica- 
tion of  rivers  is  by  one  set  of  observers  regarded  as  an 
indisputable  fact,  whilst  by  others  it  is  regarded  as  a  myth. 
The  Royal  Commission  on  Water  Supplies  in  1869  reported 
that  when  sewage  was  diluted  in  a  stream  with  not  less 
than  twenty  times  its  volume  of  water,  that  the  polluting 
matter  was  completely  oxidised  and  destroyed  during  a 
flow  of  "  a  dozen  miles  or  so."  The  Rivers  Pollution  Com- 
missioners in  1874  reported  that,  as  there  was  no  proof  of 
this,  they  had  undertaken  a  series  of  observations  and 
experiments  and  had  arrived  at  a  diametrically  opposite 
conclusion.  After  describing  the  experiments,  etc.,  they 
conclude  that  "  whether  we  examine  the  organic  pollution 
of  a  river  at  different  points  of  its  flow,  or  the  rate  of 
disappearance  of  the  organic  matter  of  sewage  or  •  urine 
when  these  polluting  liquids  are  mixed  with  fresh  water 
and  violently  agitated  in  contact  with  air,  or  finally,  the 
rate  at  which  dissolved  oxygen  disappears  in  water  polluted 
with  5  per  cent,  of  sewage,  we  are  led  in  each  case  to  the 
inevitable  conclusion  that  the  oxidation  of  the  organic 
matter  in  sewage  proceeds  with  extreme  slowness,  even 
when  the  sewage  is  mixed  with  a  large  volume  of  unpolluted 


RIVER  WATER  93 

water,  and  that  it  is  impossible  to  say  how  far  such  water 
must  flow  before  the  sewage  matter  becomes  thoroughly 
oxidised.  It  will  be  safe  to  infer,  however,  from  the  above 
results  that  there  is  no  river  in  the  United  Kingdom  long 
enough  to  effect  the  destruction  of  sewage  by  oxidation." 
In  the  same  Report  is  quoted  the  opinion  of  Sir  Benjamin 
Brodie,  F.R.S.,  "  that  it  is  simply  impossible  that  the 
oxidising  power  acting  on  sewage  running  in  mixture  with 
water  over  a  distance  of  any  length  is  sufficient  to  remove 
its  noxious  quality."  This  Royal  Report  notwithstanding, 
it  is  an  undoubted  fact  that  in  many  rivers  a  purifying 
action  is  taking  place,  and  with  great  rapidity.  Thus  the 
river  Seine,  after  becoming  horribly  polluted  as  it  runs 
through  Paris,  gradually  improves  in  appearance,  and  about 
30  miles  below  the  city  is  actually  found  upon  analysis  to 
be  purer  than  it  was  before  it  received  the  sewage  of  the 
city.  The  water  of  the  Thames  at  Hampton  Court  contains 
no  more  organic  matter  than  it  does  at  points  higher  up, 
before  it  has  received  the  sewage  of  the  towns  along  its 
course.  The  Royal  Commission  on  Metropolitan  Water 
Supply,  after  hearing  much  evidence,  concluded  that,  "After 
all,  the  main  evidence  on  which  we  have  to  base  our 
judgment  is  that  furnished  by  London  itself.  For  more 
than  thirty  years  the  inhabitants  of  London  have  been 
drinking  water  taken  from  the  Lea  and  the  Thames  above 
Teddington,  at  points  either  the  same  as  those  at  which 
the  present  intakes  are  situated  or  at  points  where  the 
chances  of  contamination  were  greater,  and  the  population 
that  has  been  thus  supplied  has  varied  from  some  two  and 
a  half  to  five  millions.  Here,  then,  we  have  an  experiment 
on  a  gigantic  scale,  largely  exceeding  in  compass  the 
aggregate  experience  of  all  the  other  places  in  which 
outbreaks  of  fever  have  been  subject  to  inquiry,  and  an 
experiment  made,  moreover,  under  the  very  conditions,  or 
at  any  rate  under  no  more  favourable  conditions  than  those 
that  are  still  in  operation  in  London.  What  has  been  the 


94  WATER  SUPPLIES 

practical  issue  of  this  prolonged  and  wide  experience? 
Every  medical  witness  that  has  appeared  before  us,  whether 
his  general  feeling  was  favourable  or  unfavourable  to  the 
water,  has  told  us  unhesitatingly  that  he  knows  of  no  single 
instance  in  which  the  consumption  of  this  water  has  caused 
disease.  This  is  the  unanimous  testimony  of  the  medical 
officers  of  health,  of  the  water  analysts,  and  of  the  bacterio- 
logical experts,  —  of  all,  in  short,  whose  attention  has 
of  necessity  been  directed  to  the  subject."  The  Com- 
missioners therefore  think  that  the  risk  of  disseminating 
disease,  even  by  admittedly  polluted  river  water,  is,  under 
conditions  similar  to  those  which  obtain  in  the  Lea  and 
the  Thames,  and  where  the  water  is  equally  carefully 
collected  and  filtered,  so  small  as  to  be  negligible. 

The  serious  outbreaks  of  typhoid  fever  in  the  Tees  valley 
in  1890-91,  which  were  investigated  by  Dr.  Barry,  a  Local 
Government  Board  inspector  of  great  experience,  were 
attributed  by  him  to  the  pollution  of  the  river  Tees  by 
sewage.  The  Medical  Officer  to  the  Local  Government 
Board,  in  his  introduction  to  this  Report,  says,  "  Seldom, 
if  ever,  has  the  fouling  of  water  intended  for  human 
consumption,  so  gross  or  so  persistently  maintained,  come 
within  the  cognisance  of  the  medical  department,  and 
seldom,  if  ever,  has  the  proof  of  the  relation  of  the  use  of 
water  so  befouled  to  wholesale  occurrence  of  enteric  fever 
been  more  obvious  and  patent."  These  outbreaks  were 
carefully  considered  by  the  Metropolitan  Commissioners, 
and  they  concluded  that  Dr.  Barry's  evidence  connecting 
them  with  the  polluted  Tees  water  was  not  conclusive. 

Amidst  such  a  conflict  of  opinion  it  is  safest  to  suspend 
one's  judgment;  but  even /the  most  ardent  advocate  of  the 
use  of  river  water  will  admit  that  it  should  receive  as  little 
sewage  as  possible,  and  that  the  sewage  should  be  previously 
subjected  to  the  most  effective  system  of  purification. 
Storage  reservoirs  also  should  be  provided,  sufficiently  large 
to  allow  of  the  average  daily  supply  being  furnished  without 


RIVER  WATER 


95 


taking  in  any  part  of  the  flood-water,  and  the  filters  should 
be  kept  in  a  thoroughly  efficient  condition.  That  the 
neglect  to  maintain  these  conditions  might  result  in  an 
outbreak  of  typhoid  fever  or  cholera  seems  possible  if  not 
even  probable,  and  the  fact  that  a  town  using  polluted  water 
has  remained  free  from  such  epidemics  for  a  series  of  years 
is  no  proof  that  such  immunity  will  be  perpetual.  In  the 
section  treating  of  "  Diseases  disseminated  by  Potable 
Waters  "  many  examples  will  be  quoted  in  which  polluted 
river  water  has  been  proved,  so  far  as  actual  proof  is 
possible,  to  have  been  the  cause  of  serious  outbreaks  of  both 
typhoid  fever  and  cholera. 

^The  amount  of  water  which  can  be  taken  from  a  river 
for  supplying  a  town  varies  according  to  (a)  the  area  of  the 
watershed,  (b)  the  topography  and  geological  character  of 
the  ground,  (c)  the  average  rainfall,  and  the  rainfall  during 
a  consecutive  series  of  dry  years,  (d)  the  distribution  of  the 
rainfall  throughout  the  year,  (e)  the  amount  of  water  which 
must  be  supplied  for  "  compensation  "  purposes,  and  (/7)  the 
facilities  for  obtaining  storage. 

The  available  watershed,  of  course,  includes  only  that 
portion  of  the  whole  watershed  which  feeds  the  river  above 
the  point  at  which  the  water  will  be  abstracted.  This  can 
only  be  ascertained  by  actual  measurement,  though  approxi- 
mate estimates  may  be  made  from  hydrographical  maps  on 
which  the  river  basins  are  defined. 

The  contour  of  the  ground  surface  also  affects  the  supply, 
for  upon  this  depends  greatly  the  rapidity  with  which  the 
rainfall,  especially  when  heavy,  will  flow  over  the  surface 
into  the  stream.  The  character  of  the  surface  and  of  the 
subsoil  will  also  affect  the  amount  which  will  flow  directly 
into  the  river,  and  the  amount  which  will  percolate  and 
pass  into  the  river  at  a  lower  level.  All  the  above  also  will 
be  factors  in  determining  the  amount  of  evaporation,  or, 
in  other  words,  of  determining  the  available  rainfall.  The 
surface  drainage  area  does  not  always  correspond  with  the 


g6  WATER  SUPPLIES 

true  drainage  area,  since  there  may  be  springs  within  the 
surface  area  fed  from  a  source  without  that  area;  and,  on 
the  other  hand,  rain  which  falls  on  the  surface  area  may 
pass  by  underground  channels  beyond  the  limits  of  the 
watershed.  All  these  possibilities  have  to  be  borne  in 
mind,  and  the  locality  carefully  examined  to  ascertain 
whether  such  conditions  exist,  and  to  what  extent  jbhey  will 
affect  the  water  supply. 

The  way  in  which  the  rainfall  in  any  particular  district 
can  be  ascertained  has  already  been  described.  The 
minimum  rainfall  for  a  year,  or  a  series  of  years,  can  only 
be  determined  from  records  continuously  taken  for  many 
years;  but  it  is  found  that,  under  ordinary  circumstances, 
the  maximum  rainfall  exceeds  the  average  by  one-third, 
whilst  the  minimum  falls  short  of  the  average  by  the  same 
amount.  The  mean  rainfall  during  the  three  driest  con- 
secutive years  is  usually  about  one-fifth  less  than  the 
average.  Thus,  where  the  average  rainfall  for  a  series  of 
years  is  30  inches  per  annum,  the  maximum  will  be  about 
40  inches,  the  minimum  20  inches,  and  the  mean  for  the 
three  driest  consecutive  years  24  inches.  Where  careful 
daily  gaugings  of  a  stream  have  been  made  for  a  few  years, 
the  proportion  of  the  rainfall  finding  its  way  into  it  can  be 
ascertained,  and  by  calculation  the  amount  which  would 
pass  into  the  river,  with  the  minimum  rainfall,  can  be 
approximately  determined.  The  following  table,  compiled 
from  the  22nd  Annual  Report  of  the  State  Board  of  Health 
of  Massachusetts,  shows  the  rainfall  received  and  collected 
during  a  series  of  years  on  the  Sudbury  River  watershed. 

During  the  sixteen  years,  1875-90  inclusive,  the  average 
rainfall  was  45.8  inches.  The  calculated  maximum  rainfall 
on  this  area  is  61.1  inches,  and  the  minimum  30.5  inches. 
The  observed  maximum  and  minimum  were  57.9  and  32.8 
inches  respectively.  The  mean  rainfall  for  the  three  driest 
years  (1882-84)  was  38.8,  whilst  the  calculated  mean  is  36.6 
inches,  so  that  doubtless  t]je  calculated  amounts  will  closely 


RIVER  WATER 


97 


approximate  to  the  truth  when  the  records  for  a  much 
longer  period  of  years  are  available.  The  percentage  of 
rainfall  collected  does  not  vary  directly  with  the  rainfall, 
and  neither  the  smallest  nor  largest  proportion  collected 
corresponded  with  the  lowest  and  highest  rainfalls ;  but  the 
results  do  not  vary  to  such  an  extent  as  to  render  it 
difficult  to  determine  approximately  the  minimum  amount 
available.  The  cause  of  this  variation  is  due  in  part  to 
the  seasonal  variation  in  the  rainfall,  and  in  part  to  the 
variation  in  the  amount  evaporated. 


Year. 

Rainfall. 

Rainfall  Collected. 

Per  Cent.  Collected. 

1875 

45-49 

20-42 

44-9 

1876 

49-56 

23-91 

48-2 

1877 

44-02 

25-49 

57-9 

1878 

57-93 

30-49 

52-6 

1879 

41-42 

18-77 

45-3 

1880 

38-18 

12-18 

31-9 

1881 

44-17 

20-56 

46-6 

1882 

39-39 

18-10 

45-9 

1883 

32-78 

11-19 

34-1 

1884 

47-13 

23-78 

30-5 

1885 

43-54 

18-92 

43-4 

1886 

46-06 

22-82 

49-5 

1887 

42-70 

24-23 

56-7 

1888 

57-46 

35-75 

62-2 

1889 

49-95 

29-06 

58-2 

1890 

53-00 

27-00 

50-9 

Mean  for  16  yrs. 

45-80 

22-67 

49-5 

A  knowledge  of  the  seasonal  rainfall  and  the  seasonal 
variation  in  the  flow  of  the  stream  is  also  absolutely  neces- 
sary, since  upon  these  factors  depend  in  a  great  measure  the 
amount  of  storage  which  will  be  required  to  collect  the 
water  during  periods  of  abundance  for  use  during  periods 
of  drought.  During  the  sixteen  years'  records  of  the 
Sudbury  River,  the  mean  daily  flow  during  the  month  when 
the  river  was  lowest  was  only  60  gallons  per  acre  of  the 
watershed;  during  the  driest  three  months  it  was  148 

7 


98  WATER  SUPPLIES 

gallons;  during  the  driest  twelve  months,  777  gallons; 
whilst  the  mean  daily  flow  for  the  whole  period  was 
1,686  gallons.  From  these  records  the  reporters  to  the 
Massachusetts  State  Board  of  Health  have  calculated  a 
table  showing  the  "  amount  of  storage  necessary  to  make 
available  different  quantities  of  water  per  day  from  each 
square  mile  of  watershed,  where  the  conditions  are  similar 
to  those  which  exist  at  Sudbury  River."  To  obtain  100,000 
gallons  per  day  per  square  mile,  the  storage  reservoir  must 
be  capable  of  holding  2,200,000  gallons  per  square  mile  of 
watershed;  to  obtain  1,000,000  gallons  per  day,  the 
reservoir  must  hold  540,000,000  gallons.  For  intermediate 
quantities  the  original  table  must  be  consulted.*  Of  course 
these  results  can  only  be  used  where  the  conditions  which 
obtain  resemble  somewhat  those  of  the  watershed  under 
consideration.  The  following  table  for  the  river  Thames 
is  calculated  from  data  given  in  the  Report  of  the  Royal 
Commission  on  Metropolitan  Water  Supply  :  — 


Year. 

Rainfall. 

Rainfall  Collected. 

Per  Cent.  Collected. 

1883 

28-4 

13-3 

46-8 

1884 

22-9 

7-0 

30-8 

1885 

29-15 

8-3 

28-5 

1886 

31-1 

11-1 

35-7 

1887 

21-3 

8-2 

38-5 

1888 

28-45 

8-9 

31-3 

1889 

25-6 

9-1 

35-5 

1890 

22-8 

5-7 

25-0 

1891 

33-3 

9-8 

29-3 

Average  of  9  yrs. 

27-0 

9-05 

33-5 

If  this  table  be  compared  with  the  corresponding  one  for 
the  Sudbury  River,  it  is  evident  that  a  considerably  larger 
proportion  of  the  rainfall  is  available  from  the  watershed 
of  the  Sudbury  than  from  that  of  the  Thames. 


*  State  Report,  1890,  p.  342. 


RIVER  WATER  gg 

Mr.  Beardmore  calculates  that  during  summer,  the 
Thames,  Severn,  Loddon,  Medway,  and  Nene,  which  flow 
over  a  variety  of  geological  strata,  only  carry  off  less  than 
one-eighth  of  the  rainfall,  whilst  the  Mimram  and  Wandle, 
which  arise  in  and  flow  through  chalk  districts  only,  yield 
nearly  half  the  total  rainfall.  Certain  rivers  are  much 
more  constant  in  their  flow  than  others,  the  result  de- 
pending chiefly  upon  the  conformation  of  the  watershed 
and  the  character  of  the  subsoil.  If  the  stream  be  fed 
chiefly  with  surface  water  the  variation  will  be  very 
considerable,  whilst  if  fed  chiefly  from  the  subsoil  the  flow 
will  be  comparatively  uniform.  All  these  factors,  therefore, 
have  to  be  taken  into  consideration  when  estimating  the 
available  supply  and  the  amount  of  storage  necessary. 

Where  there  are  riparian  owners  having  a  right  to  the 
use  of  the  water  for  any  purpose,  as  for  manufacturing,  or 
as  a  motive  power,  further  complications  are  introduced. 
Sufficient  water  must  be  allowed  to  pass  down  the  river  to 
satisfy  all  their  reasonable  requirements.  Only  the  amount 
in  excess  of  this  can  be  appropriated,  and  as  during  seasons 
of  drought  they  may  require  the  whole  flow  of  the  river, 
the  impounding  reservoirs  must  be  large  enough  to  store 
water  during  seasons  of  abundance  sufficient  to  tide  over 
these  periods  when  none  can  be  collected. 

The  quantity  of  water  which  must  be  stored  to  equalise 
the  supply  during  the  longest  period  of  drought  which  may 
possibly  occur  can  only  be  determined  when  the  average 
daily  demand  is  approximately  known,  and  the  whole  of 
the  conditions  above  referred  to  have  been  carefully 
investigated.  The  number  of  days'  storage  required  varies 
in  this  country  from  120  to  300;  the  smaller  quantity  only 
being  required  on  the  western  side,  where  the  rainfall  is 
heavy  and  the  number  of  rainy  days  considerably  above 
the  average.  In  the  eastern  counties,  where  exactly  the 
opposite  conditions  obtain,  about  ten  months'  storage  may 
be  necessary. 


ioo  .  WATER  SUPPLIES 

The  amount  of  storage  required  may  be  calculated  from 
the  rainfall  statistics  only,  or  from  the  stream  gaugings,  but 
both  must  be  considered  if  the  result  is  to  be  reliable.  The 
gaugings  may  be  effected  by  various  methods  :  (a)  by  means 
of  sluices;  (b)  by  aid  of  current  meters;  (c)  by  means 
weirs ;  (d)  by  gauging  the  surface  velocity.  Where  a  rough 
approximation  only  is  desired  a  straight  portion  of  the 
stream  may  be  selected  which  is  tolerably  uniform  in  width 
and  section,  and  where  the  water  flows  smoothly,  or  where 
by  a  little  labour  such  uniformity  may  be  produced.  By 
plumbing  the  depth  at  different  points  across  the  stream 
and  measuring  the  width,  the  cross  section  can  easily  be 
calculated.  The  length  of  the  selected  portion,  20  yards  or 
more,  must  be  marked  off,  and  the  time  noted  which  it 
takes  a  chip  or  float  to  traverse  this  length  in  mid-stream 
on  a  calm  day.  The  mean  velocity  of  the  whole  body  of 
the  water  may  be  taken  as  .75  that  of  the  surface  velocity. 
These  data  are  sufficient  to  give  the  volume  required. 

For  example,  the  area  of  a  section  of  a  stream  is  found 
to  be  45  square  feet,  and  the  time  taken  by  a  float  in 
traversing  a  distance  of  60  feet  is  80  seconds.  Required 
the  flow  in  gallons  per  day. 

45  x  60  x  -75  =  25.3125  =  flow  in  cubic  feet  per  secon(i. 
25-3125  x  60  x  60  x  24  x  6-25  =  13,668,750  gallons  per  24  hours. 

The  ratio  of  the  mean  to  the  surface  velocity  is  not  a 
constant,  and  its  value  is  variously  estimated  by  engineers 
from  the  results  of  actual  experiments.  It  varies  with  the 
rapidity  of  flow,  the  nature  of  the  channel,  depth  of 
water,  or  form  of  cross  section,  but  the  first  named  is 
probably  by  far  the  most  important  factor.  Mr.  Beardmore 
adopts  the  formula  U  =  V  +  2'5  —  V/5V  where  U  equals  the 
mean,  and  V  the  surface  velocity  per  minute.  This  formula 
gives  the  following  values  for  U  :  — 


RIVER  WATER 


101 


Surface  Velocity 
in  Feet 
per  Minute. 

Mean  Velocity. 

Value  of  U 
in  terms  of  V. 

5 

2-5 

•5 

10 

5-5 

•55 

20 

12-5 

•625 

50 

36-5 

•73 

100 

80-2 

•802 

200 

170-9 

•885 

Where  greater  accuracy  is  required  and  the  stream  is  large, 
a  current  meter  may  be  employed. 

"  Having  fixed  on  the  station  where  the  cross  section  of 
a  large  river  is  to  be  taken  and  the  velocities  ascertained, 
take  a  number  of  soundings  across  the  stream,  at  8,  10,  or 
12  points,  according  to  the  breadth.  These  lines  of  sounding 


FIG.  10. 

divide  the  section  into  a  number  of  trapezia,  and  the  area 
of  each  of  these  is  to  be  calculated.  Then,  at  a  point 
half-way  between  each  of  the  two  lines  of  sounding,  is  to 
be  fixed  a  small  boat  containing  the  current  meter  (Fig.  10), 
by  means  of  which  5,  6,  or  7  velocities  are  to  be  determined 
in  the  same  vertical  line.  The  arithmetical  mean  of  these 


loa  WATER  SUPPLIES 

is  then  to  be  multiplied  by  the  area  of  the  trapezium  to 
which  they  apply.  The  sum  of  these  products  is  evidently 
the  discharge  of  the  river  —  it  is  equivalent  to  the 
total  sectional  area  multiplied  by  the  mean  velocity " 
(Hughes's  "  Waterworks,"  quoted  from  D'Aubuisson's 
Traite  d'Hydraulique  a  I' usage  des  Ingenieurs). 

In  artificially  constructed  channels  of  uniform  cross 
section,  such  as  canals,  culverts,  and  pipes  (the  two  latter 
may  be  running  full,  but  must  not  be  under  pressure), 
various  formulae  have  been  devised  for  estimating  the  flow 
from  the  fall  per  mile  and  the  hydraulic  mean  depth. * 
Beardmore's  modification  of  Eytelwein's  formula  is  the 
one  usually  employed — 


U  =  55 


where  U  equals  the  mean  velocity  in  feet  per  minute,  K,  the 
hydraulic  mean  depth,  and  H  the  fall  in  feet  per  mile. 

Example.  —  In  a  circular  channel  of  2.5  feet  diameter, 
having  a  fall  of  five  feet  per  mile,  and  running  exactly  half 
full  of  water,  what  is  the  flow  in  cubic  feet  per  minute  ? 


=  137'5. 


The  area  of  a  section  of  the  water  is  -  —  =  2.453  feet. 

A 

This,   multiplied  by  the  velocity,    137.5,   gives   a  yield   of 
337.3  cubic  feet  per  minute. 

Streams  of  any  magnitude  are  usually  gauged  by 
engineers  by  the  aid  of  artificially  constructed  weirs. 
Theoretically  the  velocity  with  which  the  water  passes  over 
the  weir  is  that  which  a  body  would  acquire  in  falling 

*  The  hydraulic  mean  depth  is  the  sectional  area  of  the  water  divided 
by  the  wetted  perimeter.  In  circular  pipes  running  full,  3-14d  equals 
the  wetted  perimeter,  and  d2>785  the  cross  section  of  the  water  ;  R 
therefore  equals  \d. 


RIVER  WATER  103 

through  a  distance  equal  to  the  difference  between  the 
surface  level  of  the  water  above  the  weir  and  the  surface 
of  the  weir  itself.  A  body  falling  from  rest  acquires  at  the 
end  of  one  second  a  velocity,  g,  which  is  approximately 
32  feet  per  second.  The  mean  velocity  at  the  end  of  any 

number  of  seconds,  t,  will  be  ^-i_!  =  -Jr,  the  space  traversed, 

A         -j 

s,  in  that  time  will  be  -/,  and  the  velocity  at  the  end  of 
A 

that  period  tg.  Eliminating  t,  we  find  that  V2  =  2sg  = 
2  x  32  x  s,  therefore 

v  =  8  V  s. 

Theoretically,  therefore,  the  velocity  with  which  water 
passes  over  the  actual  surface  of  the  weir  is  eight  times 
the  square  root  of  the  difference  in  level  above  referred  to. 
But  this  is  the  lowermost  stratum  of  the  water  only,  the 
strata  above  having  a  less  velocity,  decreasing  upwards  as 
the  square  root  of  the  depth  from  the  surface  level.  The 
mean  velocity  of  all  the  strata  will  be  that  of  the  particles 
at  |  the  depth  of  the  lowermost,  therefore 
. 

*>  =  §8  ,/s  =  5i  Js. 

Unfortunately  friction  has  to  be  taken  into  account,  and 
as  this  varies  with  the  shape  of  the  weir,  its  width,  etc., 
the  above  formula  has  little  more  than  theoretical  interest. 
Numberless  experiments  have  been  recorded  and  many 
formulae  deduced  therefrom  for  weirs  of  different  kinds. 
Here,  however,  it  is  only  necessary  to  refer  to  the  one  most 
frequently  employed,  that  derived  from  Mr.  Blackwell's 
experiment  made  on  the  Kennet  and  Avon  Canal  on  the 
flow  of  water  over  2-inch  planks.  Let  Q  equal  the  quantity 
of  water  flowing  over  the  weir  in  cubic  feet  per  minute, 
then 

Q  =  cw  Vs3- 


io4 


WATER  SUPPLIES 


Where  w  =  the  width  in  feet,  s  the  depth  of  water  in  inches, 
and  c  =  a  constant  multiplier,  found  by  experiment  and 
given  in  the  following  table  (quoted  from  Slaggs'  Water 
Engineering)  :  — 


Depth  s  =  1  inch 
=  2  inches 


=  4 
=  5 
=  6 
=  7 


Value  of  c  =  3-50 
=  4-25 
=  4-44 
=  4-44 
=  4-62 
-4-57 
=  4-61 
=  4-48 
=  4-44 


For  depths  of  3  inches  and  upwards  c  may  evidently  be 
taken  as  4.5.  As  an  example,  it  is  required  to  calculate 
the  flow  over  a  weir  of  5  feet  in  width,  the  level  of  which 
is  6  inches  below  the  even  surface  of  the  water. 

Since  s  =  6,  c  =  4-5  and  w  =  5 
Q  =  4-5  x  5  x  J& 
Q  =  333  cubic  feet  per  minute. 

Under  certain  circumstances,  as  where  a  lock  gate  and 
sluice  are  available,  the  flow  may  be  determined  from  the 
area  of  the  sluice  and  the  vertical  distance  between  the 
centre  of  the  sluice  and  the  level  of  the  water  in  the 
stream.  Theoretically  the  velocity  of  the  water  passing 
through  the  sluice  would  be  8  Js,  but  from  friction  and 
other  causes  it  is  always  less  than  this.  With  very  small 
sluices  of  from  1  to  16  square  inches  area,  Poncelet  and 
Lesbros'  factor,  .62  may  be  taken  as  approximately  correct. 
If  therefore  the  area  of  the  sluice  A  be  known,  the  flow 
per  second  will  be  :  — 

Q  =  A  x  '62  x  8  *Js  =  approximately  5  A  Js. 

If  A  and  s  be  expressed  in  feet,  Q  will  be  the  flow  in  cubic 
feet  per  second. 


RIVER  WATER  105 

Where  the  river  is  of  considerable  dimensions,  and  it  is 
desired  to  record  the  variations  in  the  flow  automatically, 
a  tide-gauge  may  be  used  (Fig.  11). 

By  aid  of  such  an  instrument  the  rise  and  fall  of  the 
float  is  recorded  on  a  revolving  cylinder,  so  that  not  only 
the  extent  of  the  variations,  but  the  exact  time  at  which 
they  occurred  is  registered. 


FIG.  11. 


Where  the  amount  of  water  to  be  abstracted  from  a  river 
is  very  small  compared  with  its  volume,  of  course  all  these 
elaborate  investigations  are  unnecessary.  In  such  cases 
also,  storage  will  only  be  required  to  supply  the  town 
during  periods  when  the  river  is  in  flood  and  the  water 
turbid. 

In  exceptional  cases  only  can  river  water  be  abstracted 
at  a  point  sufficiently  high  to  supply  a  town  by  gravitation. 


106  WATER  SUPPLIES 

Usually  the  water  is  pumped  into  storage  reservoirs,  from 
which  it  flows  on  to  the  filter  beds,  and  it  may  again  require 
to  be  pumped  after  filtration  into  service  reservoirs  at  such 
an  elevation  as  to  permit  of  the  water  supplying  the  town 
by  gravitation.  Service  pipes  may  be  attached*  to  the 
rising  main  if  houses  have  to  be  supplied  en  route.  When 
pumping  is  going  on  the  flow  will  be  from  the  pumping 
station  to  the  houses,  but  when  the  pumping  ceases  the 
flow  will  be  in  the  contrary  direction,  from  the  service 
reservoir.  The  water  taken  from  the  Thames  and  Lea  for 
the  supply  of  the  metropolis  is  all  pumped  into  service 
reservoirs  in  order  to  obtain  the  necessary  pressure,  the 
height  to  which  it  is  lifted  being  on  an  average  200 
feet. 

Limited  supplies  of  water  can  be  obtained  from  streams 
having  a  good  fall,  by  aid  of  rains,  turbines,  or  water-wheels, 
when  the  place  to  be  supplied  is  at  too  great  an  elevation 
to  be  directly  supplied  by  gravitation.  These  automatic 
pumping  machines  will  be  described  in  a  later  section. 

A  large  number  of  towns  in  England  derive  their  water 
supplies  from  rivers.  In  the  Tees  valley,  Darlington,  Stock- 
ton, Middlesborough,  and  several  smaller  towns  are  supplied 
from  the  Tees ;  Durham  is  supplied  from  the  Wear,  Carlisle 
from  the  Eden,  Ripon  from  the  Ure,  York  from  the  Ouse, 
Knaresborough  from  the  Nidd,  Leeds  from  the  Wharfe  and 
Washburn,  Doncaster  from  the  Don,  Wakefield  in  part  from 
the  Calder,  Ely  from  the  Ouse,  Leamington  from  the  Learn, 
Shrewsbury,  Worcester,  and  Tewkesbury  from  the  Severn 
(Cheltenham  also  occasionally),  Plymouth  from  the  Mew, 
Sandown  (Isle  of  Wight)  from  the  Yare,  etc.  On  account  of 
the  prevalence  of  typhoid  fever  in  certain  of  these  towns 
(Stockton,  Darlington,  Middlesborough,  York,  and  Newark, 
for  example)  the  possibility  of  obtaining  water  supplies 
from  other  sources  has  been  considered.  On  the  other 

*  There  are  objections  to  this  procedure. 


RIVER  WATER  107 

hand,  certain  towns  are  contemplating  improving  their 
present  supplies  by  resorting  to  rivers.  Cheltenham,  for 
example,  is  completing  works  for  augmenting  its  present 
supply  by  drawing  from  the  Severn  at  Tewkesbury.  It  is 
now  supplied  in  part  by  spring  water  collected  in  brick- 
built  reservoirs  (this  water  when  stored  has  a  tendency  at 
certain  seasons  of  the  year  to  acquire  a  disagreeable  odour 
from  the  growth  of  Chara  and  numerous  minor  vegetable 
organisms),  and  in  part  by  the  head  waters  of  the  Chelt, 
which  is  also  impounded  in  a  reservoir.  This  reservoir  will 
hold  100,000,000  gallons,  or  about  100  days'  supply  for  the 
town,  and  is  usually  full  to  overflowing  about  the  end  of 
March ;  it  then  loses  water  pretty  continuously  until 
November,  when  again  the  feeders  exceed  the  draught. 
100,000  gallons  a  day  have  to  be  turned  down  the  Chelt 
as  compensation  water.  This  water  is  subject  at  certain 
seasons  to  acquire  a  red  tint  from  a  growth  in  it  of 
Crenothrix.  The  closing  of  surface  wells,  and  the  increasing 
demand  for  water  for  water-closets  and  for  flushing  sewers, 
and  other  municipal  purposes,  has  on  several  occasions  run 
the  reservoirs  so  low  as  to  cause  considerable  anxiety. 
There  is  within  five  or  six  miles  of  the  town  a  perennial 
supply  of  pure  water  from  springs,  which  form  the  head 
waters  of  the  Thames,  but  Parliament  has  refused  to  allow 
them  to  be  diverted  for  the  use  of  the  town.  In  1881 
powers  were  obtained  for  bringing  water  from  the  Severn 
at  Tewkesbury,  and  for  supplying  that  town  and  the 
villages  en  route.  The  recent  dry  seasons  and  the  increased 
requirements  of  the  town  have  impelled  the  Cheltenham 
Corporation  to  utilise  these  powers,  and  the  filter  beds 
existing  at  Tewkesbury  having  been  largely  augmented, 
a  water  main  has  been  laid  from  Tewkesbury  to  Cheltenham 
(9  miles),  and  powerful  pumping  engines  installed.  The 
Medical  Officer  of  Health  says  that  the  water  is  wonderfully 
good,  and  the  volume  magnificent.  That  it  receives  the 
sewage  of  several  towns  along  its  course  is  acknowledged, 


io8  WATER  SUPPLIES 

but  that  there  is  any  evidence  of  this  pollution  at  Tewkes- 
bury  is  denied.  Worcester  has  taken  its  supply  from  the 
Severn  for  forty  years,  and  although  the  nitration  is  said 
to  have  been  in  past  time  far  from  perfect,  it  has  suffered 
nothing.  This  town,  however,  pours  its  sewage  into  the 
river  at  a  point  seventeen  miles  above  the  Cheltenham 
intake,  and  a  mandamus  has  been  issued  to  compel  the  town 
to  purify  its  sewage.  Between  Worcester  and  Tewkesbury 
very  little  sewage  enters  the  Severn.  With  the  Worcester 
sewage  diverted  or  purified,  the  Medical  Officer  and  engineer 
consider  that  the  Severn  water,  properly  collected  and 
filtered,  will  afford  an  abundant  and  perfectly  wholesome 
supply  to  Cheltenham,  and  more  especially  as  the  towns 
already  deriving  their  water  supplies  from  the  Severn  have 
never  been  unduly  affected  by  typhoid  fever.  During  the 
last  three  dry  summers  the  Severn  supply  has  had  to  be 
largely  resorted  to  by  Cheltenham,  and  during  the  periods 
of  its  use  no  increase  of  typhoid  fever  cases  have  occurred. 
The  amount  of  typhoid,  in  fact,  has  never  been  less  in 
Cheltenham  than  during  these  years. 

Table  VII.  (Chapter  X.)  contains  the  analyses  of  several 
typical  samples  of  river  water,  including  the  filtered  waters 
supplied  by  the  various  London  companies,  during  August 
1892,  derived  from  the  rivers  Thames  and  Lea. 


CHAPTER  VIII. 

QUALITY  OF  DRINKING  WATERS. 

MUCH  has  already  been  said  about  the  suitability  of  waters 
from  various  sources  for  domestic  use,  and  fortunately  it 
may  be  taken  as  being  generally  true  that  the  best  water  for 
drinking  purposes  is  also  the  best  for  cooking,  washing,  and 
other  domestic  requirements,  and  also  for  probably  all 
manufacturing  processes.  A  high  degree  of  purity  is  not 
necessary  in  the  latter  case;  hence  a  water  which  may  be 
totally  unfit  for  drinking  may  still  be  of  value  for  many 
other  purposes;  but  as  dual  supplies  introduce  complica- 
tions, and  usually  mean  additional  expenditure,  it  is  an 
undoubted  advantage  to  have  a  single  supply  equally  well 
adapted  for  all  uses.  As  health,  however,  is  of  paramount 
importance,  a  pure  water  supply  is  an  absolute  necessity  for 
domestic  use,  and  it  is  only  where  the  supply  is  limited, 
or  the  water  is  unfitted  in  some  way  (as  by  being  too  hard), 
or  is  too  expensive  for  manufacturing  purposes,  that  there 
will  be  any  demand  for  an  additional  supply.  In  many 
towns  the  requirements  of  manufacturers  are  met  by  the 
laying  of  special  mains  conveying  water  from  a  river,  or 
some  other  source,  yielding  water  too  impure  for  domestic 
use,  yet  perfectly  well  adapted  for  their  special  require- 
ments. Such  water  may  also  be  utilised  for  flushing  sewers, 
etc.  On  the  sea-coast  sea-water  is  sometimes  used  for 
flushing  sewers,  etc.,  especially  where  it  is  cheaper  to  pump 
it  than  use  the  domestic  supply,  or  where  the  latter  is  not 
too  abundant. 

(109) 


no  WATER  SUPPLIES 

The  characteristics  of  a  good  potable  water  are  freedom 
from  colour,  odour,  taste,  turbidity,  and  excess  of  saline 
matter  and  the  total  absence  -of  all  injurious  substances, 
whether  of  animal,  vegetable,  or  mineral  origin. 

Colour. — A  hygienically  pure  water  is  almost  invariably 
quite  colourless  when  viewed  in  small  bulk,  as  in  a  tumbler, 
though  when  looked  at  in  a  reservoir,  or  in  a  tube  about 
2  feet  long,  it  will  have  a  faint  bluish  tint. 

Professor  Tyndall  showed  that  when  a  powerfully  con- 


FIG.  12. — Tubes  for  comparing  the  colours  of  potable  waters. 

densed  beam  was  caused  to  traverse  a  sample  of  water,  the 
amount  of  light  scattered  depended  upon  the  quantity  of 
impurity  present.  But  "  an  amount  of  impurity  so 
infinitesimal  as  to  be  scarcely  expressible  in  numbers,  and 
the  individual  particles  of  which  are  so  small  as  wholly  to 
elude  the  microscope,  may,  when  examined  by  the  method 
alluded  to,  produce  not  only  sensible,  but  striking,  effects 
upon  the  eye."  Experimenting  with  sea-water,  he  found 
that  a  blue  colour  corresponded  with  a  high  degree  of 
purity.  A  yellow-green  water  in  the  luminous  beam 
appeared  exceedingly  thick  with  very  fine  particles,  and  a 
bright  green  water,  though  much  more  pure  than  the 
yellow-green,  was  far  more  impure  than  the  blue.  A  green 
or  yellow  tint  usually  indicates  the  presence  of  vegetable 
or  animal  matters;  a  brown  tint  is  almost  invariably  due 
to  peat;  whilst  a  reddish  tint  indicates  the  presence  of 
iron.  Surface  waters  from  hills  and  moorlands  often  contain 


QUALITY  OF  DRINKING  WATERS  in 

peaty  matter  in  solution  and  are  discoloured  thereby,  but 
this  discolouration  forms  only  a  sentimental  objection  to 
the  water,  unless  excessive,  and  the  peat  does  not  appear  in 
any  way  to  affect  the  health  of  those  who  use  it.  Such 
waters  are  usually  very  soft  and  well  adapted  for  manu- 
facturing purposes  generally,  but  there  are  some  processes, 
as  the  making  of  the  finest  qualities  of  paper,  in  which  the 
use  of  peaty  water  is  objectionable.  Some  bleaching  action 
takes  place  when  such  water  is  freely  exposed  to  sunlight 
and  air,  as  in  lakes  and  large  reservoirs.  From  observations 
made  in  Massachusetts  it  was  found  that  water  "  must  be 
stored  several  months  to  cause  any  material  reduction  in 
colour,  and  from  six  months  to  a  year  in  order  to  remove 
practically  all  of  it."  A  filter  of  sand  and  loam  removed 
the  whole  of  the  colour  from  the  water  of  the  Merrimac 
River  for  two  years.  During  the  third  year  the  filtered 
water  was  occasionally  coloured;  during  the  fourth  and 
fifth  year  the  effluent  from  the  filter  "  was  very  slightly  but 
uniformly  coloured."  New  sand  would  therefore  appear 
to  be  a  more  efficient  colour-remover  than  sand  which  has 
been  in  use  as  a  filtering  material  for  a  length  of  time. 

Where  the  water  has  a  reddish  or  reddish-brown  tint  due 
to  the  presence  of  iron,  access  of  air  causes  it  quickly  to 
acquire  an  opalescent  appearance,  from  the  formation  of  a 
more  highly  oxygenated  and  insoluble  compound  of  iron. 
This  deposits  slowly  and  the  water  loses  its  colour.  The 
objectionable  character  of  such  water  for  washing  purposes 
is  well  known. 

Odour. — Absolutely  pure  water  is  odourless,  and,  with 
rare  exceptions,  so  are  all  hygienically  pure  waters.  Peaty 
waters,  especially  when  warmed  and  shaken  in  a  bottle  with 
air,  give  off  a  peculiar  and  characteristic  odour.  Waters 
from  certain  sources,  though  quite  free  from  pollution,  have 
an  odour  of  sulphuretted  hydrogen  (rotten  eggs).  Where 
this  is  strong  and  persistent  the  water  is  classified  amongst 
mineral  waters  as  "  sulphuretted,"  In  some  parts  of  Essex 


ii2  WATER  SUPPLIES 

the  water  derived  from  veins  of  sand  beneath  the  boulder 
clay  has  a  faint  but  decided  odour  of  this  gas ;  the  smell 
entirely  disappears  upon  leaving  the  water  exposed  to  the 
air  for  a  short  time  in  a  bucket  or  tank.  In  these  districts, 
however,  the  inhabitants  will  drink  any  kind  of  ditch  or 
pond  water  rather  than  this,  so  convinced  are  they  that  such 
a  smell  can  only  proceed  from  the  vilest  sources.  With 
these  exceptions  any  water  giving  off  an  odour  when 
warmed  must  be  considered  impure,  and  therefore  in- 
admissible as  a  domestic  supply.  Odorous  waters  appear 
to  be  much  more  commonly  met  with  in  some  districts,  and 
in  some  seasons,  than  in  others.  In  Massachusetts,  out  of 
1,404  samples  of  drinking  water  examined,  from  reservoirs, 
ponds,  lakes,  rivers  and  brooks,  only  275  were  entirely 
destitute  of  odour,  458  had  a  "  vegetable  or  sweetish " 
odour,  202  a  "  grassy  "  odour,  84  a  "  mouldy  "  odour,  146  an 
"  aromatic  "  odour,  47  a  "  fishy  "  odour,  92  a  "  disagree- 
able "  odour,  and  100  an  "  offensive  "  odour.  Mr.  G.  N. 
Calkins,  who  has  made  a  special  study  of  this  subject, 
concludes  that  there  are  three  classes  of  odours :  (1)  odours 
of  chemical  or  putrefactive  decomposition,  (2)  odours  of 
growth,  and  (3)  odours  of  physical  disintegration — the  two 
latter  being  probably  due  to  odorous  oils.  Theoretically, 
the  odours  of  a  water  may  be  due  to  dissolved  or  suspended 
matters  of  mineral  origin,  but  no  such  substances  are  known 
to  affect  great  bodies  of  water.  Decaying  vegetable  matter, 
he  thinks,  is  responsible  for  the  "  vegetable  and  sweetish  " 
odours,  and  dead  animal  matter  for  the  "  offensive  "  odours. 
The  "  grassy "  and  "  mouldy "  odour  cannot  yet  be  ex- 
plained. The  "  aromatic  "  and  "  fishy  "  odours  are  more 
important,  since  they  are  prone  to  develop  at  certain 
seasons  of  the  year  in  waters  which  at  other  periods  are 
quite  destitute  of  smell.  These  are  invariably  surface 
waters  which  have  been  stored  for  some  time  in  open 
reservoirs. 

The  fishy  odour  is  said  to  be  due  to  various  Infusorians, 


QUALITY  OF  DRINKING   WATERS  113 

one  of  which,  the  Uroglena  Americana,  has  during  the  past 
two  or  three  years  infested  several  of  the  drinking  waters 
of  the  State. 

Professor  Remsen,  who  investigated  the  cause  of  the 
"  cucumber  "  odour  *  of  the  Boston  water  in  1878,  attri- 
buted it  to  the  decomposition  of  a  fresh  -  water  sponge 
(Spang  ilia  ftuviatilis).  Mr.  Rafter  attributed  the  disagree- 
able fishy  odour  and  taste  of  a  water  which  he  examined  to 
the  presence  of  Volvox  globator,  and  I  have  observed  a 
similar  coincidence  in  a  public  water  supply  in  this  country. 

From  time  to  time  an  organism  "  barely  visible  to  the 
naked  eye,"  globular  in  form,  greenish  yellow  in  colour,  and, 
on  superficial  examination,  closely  resembling  Volvox 
globator,  has  been  found  in  several  of  the  Massachusetts 
water  supplies,  and  recently  it  appeared  in  great  abundance 
in  the  ponds  supplying  Norwood  and  Plymouth.  The  water 
in  the  ponds  had  no  marked  odour,  but  as  delivered  from 
the  taps  in  the  towns  it  had  a  most  objectionable  smell. 
This  colony-forming  infusorian  was  found  to  belong  to  the 
genus  Uroglena.  Three  species  are  described,  but  one  only, 
the  Uroglena  Americana,  appears  to  impart  an  odour  to 
water.  When  in  a  state  of  disintegration  it  liberates  an 
oil-like  substance  with  an  intensely  disagreeable  smell.  As 
this  species  has  frequently  been  mistaken  for  Volvox, 
possibly  in  cases  where  bad  odours  have  been  attributed  to 
the  latter  they  were  really  due  to  the  Uroglena.  Such 
appears  to  have  been  the  case  at  Middleton  and  Meriden, 
Connecticut,  in  1889.  The  organism  was  found  in  great 
abundance  in  the  reservoirs,  but  was  absent  in  the  tap 
water,  and  the  latter  alone  had  any  odour.  Apparently 
while  traversing  the  water-mains  the  delicate  structure 
becomes  completely  disintegrated,  liberating  the  strongly- 
smelling  oily  constituent.  Bursaria  gastris  gives  a  sea-weed 

*  "  Odours  in  Drinking  Waters " :  Report  of  Massachusetts  State 
Board  of  Health,  1892. 

8 


i!4  WATER  SUPPLIES 

like  odour,  Cryptomonas  furnishes  a  "  candied  violet " 
odour,  Asterionella  and  Tabellaria  (Diatoms)  an  "  aro- 
matic "  odour. 

Crenothrix,  a  fungoid  growth  of  thread-like  form,  can 
only  thrive  in  water  containing  protoxide  of  iron  and 
organic  matter,  and,  by  its  decomposition,  often  causes 
water  to  acquire  a  disagreeable  odour  and  taste.  The 
Berlin  water  supply  from  wells  sunk  near  the  Tegeler  Lake 
had  to  be  abandoned  on  account  of  the  abundant  growth  of 
this  organism.  Its  appearance  in  the  Rotterdam  water 
supply  led  to  the  formation  of  the  "  Rotterdam  Crenothrix 
Commission,"  and  Prof.  Hugo  de  Vries  reported  that 
Crenothrix  was  not  a  ground  water  organism  as  was 
generally  supposed,  but  that  it  was  found  in  many  surface 
waters.  As  the  result  of  his  observations  and  experiments, 
he  expressed  the  opinion  that  two  factors  are  necessary  for 
its  growth  to  become  so  rapid  as  to  render  a  water 
unpalatable.  These  two  factors  are — the  presence  of  de- 
composing organic  matter,  and  the  presence  of  protosalts 
of  iron.  For  a  detailed  account  of  this  organism  and  its 
relation  to  water  supplies,  an  exhaustive  article  by  Prof. 
W.  F.  Sedgwick,  in  the  Technological  Quarterly,  Boston, 
1890,  may  be  consulted.  In  the  Annual  Report  of  the 
Massachusetts  State  Bo<ard  of  Health,  there  is  also  a  mass 
of  information  bearing  upon  this  subject;  and  in  Public 
Health  for  October,  1896,  Dr.  Garrett  describes  the  effect 
of  this  organism  on  the  Cheltenham  water  supply.  This 
water  contains  a  trace  of  iron,  and  in  the  spring  of  that 
year  it  became  "  rather  red  and  turbid  "  and  at  the  same 
time  acquired  an  unpleasant  odour.  A  little  later  the 
whole  of  the  water  in  a  particular  reservoir  was  observed  to 
be  affected.  In  about  three  months  matters  returned 
to  their  normal  condition.  The  organism  which  caused 
this  phenomenon  Dr.  Garrett  calls  Crenothrix  polyspora 
(var.)  Cheltoniensis.  His  paper  contains  a  very  full  account 
of  this  organism,  and  is  well  illustrated.  Dr.  Garrett  in  the 


QUALITY  OF  DRINKING   WATERS  115 

same  paper  mentions  that  the  water  in  the  lake  at  Pittville 
Park  had  turned  a  bluish-green  colour  and  acquired  a 
strong  odour.  In  this  water  he  found  a  species  of 
Anabcena  of  the  Nostoc  order,  and  a  yellow-green  monad. 
To  these  he  attributes  the  colour  and  odour. 

In  1898  I  was  consulted  with  reference  to  a  large  public 
supply  which  had  become  infested  with  a  vegetable  growth 
giving  the  water  a  very  objectionable  appearance  and  an 
ammoniacal  fishy  odour.  The  growth  consisted  of  an 
unbranched,  multicellular  chlorophylous  alga  corresponding 
to  the  Microsporon  vulgaris  of  Cooke,  but  better  known  as 
the  Conferva  Bombycina  of  Kutzing.  When  this  organism 
dies  and  breaks  up,  the  odorous  products  are  formed. 

Many  times  during  recent  years  I  have  been  called  upon 
to  examine  well  waters  which  had  suddenly  developed  an 
unpleasant  appearance  and  odour.  These  cases  almost 
invariably  occur  in  the  late  summer  and  autumn,  and  the 
changes  are  due  to  the  growth  of  a  Crenothrix. 

Waters  most  usually  affected  by  these  growths  contain 
traces  of  organic  matter  in  solution,  and  often  traces  of 
iron,  but  it  will  be  noted  that  certain  waters  such  as  those 
derived  from  the  base  of  the  oolitic  escarpment,  which  are 
of  great  organic  purity  and  in  every  way  admirable,  when 
stored  in  open  reservoirs  exhibit  a  great  tendency  to  serious 
deterioration  by  the  growth  of  Chara,  as  well  as  numerous 
microscopic  vegetable  organisms — Volvox,  Oscillatoria,  etc. 
— which  give  the  water  a  disagreeable  odour,  flavour  and 
appearance.  No  such  growths  occur  in  the  same  water 
when  stored  in  covered  reservoirs,  the  presence  of  light 
being  absolutely  necessary  for  their  growth  and  multiplica- 
tion. 

At  Syracuse,  N.  Y.,  the  water  frequently  became  offensive 
during  the  autumn  from  the  growth  of  vegetable  matter  in 
the  lake.  During  the  last  two  years  men  have  been 
employed  to  skim  off  all  such  growths  as  they  appeared, 
and  the  water  has  not  been  tainted  since. 


n6  WATER  SUPPLIES 

At  Bolton  (Lancashire)  the  water  supply  in  July,  1891, 
gave  rise  to  some  alarm,  as  it  had  somewhat  suddenly 
acquired  a  "  fishy "  odour  and  taste.  Dr.  Adams,  the 
Medical  Officer  of  Health,  attributed  the  disagreeable 
odour  to  various  forms  of  fresh-water  Algse,  but  more 
especially  to  Conferva  Bombycina,  since  this  species  when 
decomposing  yields  foetid  gases,  "  the  smell  of  which 
resembles  that  of  fish  not  in  very  fresh  condition/' 
Ho  regarded  the  growth  as  being  fostered  by  the 
presence  of  phosphates  derived  from  manure  and  sewage 
on  the  watershed  area.  As  fishes  feed  on  such  vege- 
table matters,  Dr.  Adams  advised  stocking  the  reser- 
voir with  fish,  an  experiment  which  has  been  tried 
elsewhere,  with  doubtful  results.  At  Cheltenham,  in 
September,  1891,  the  water  derived  from  an  uncovered 
reservoir  fed  by  springs  was  found  to  have  acquired  this 
fishy  odour  and  flavour.  These  springs  supply  three 
reservoirs,  A,  B,  and  C.  A  is  covered  over,  B  and  C 
uncovered.  The  open  reservoir,  C,  was  the  one  in  which 
the  water  was  affected,  and  it  was  found  when  emptied  that 
upon  the  sides  and  bottom  there  was  a  considerable  growth 
of  Chara  foetida.  Dr.  Garrett,  the  Medical  Officer  of 
Health,  says :  "  This  plant  is  infested  at  all  times  with 
parasites,  but  during  the  time  its  cells  are  breaking  down, 
the  entire  bulk  of  water  contained  in  the  reservoir  swarms 
with  living  organisms,  varying  in  size  from  the  Entomos- 
traca  that  are  easily  visible  to  the  naked  eye,  to  the  most 
minute  Protococci  and  other  unicellular  organisms  which 
require  a  high  power  of  the  microscope  to  be  distinguished/' 
Species  of  Volvox  were  very  numerous ;  species  of  Nostoc 
and  filaments  of  OscillatoricE  were  also  found.  Paramecia, 
Vorticellce,  Rotifer  ce,  Anguillulce,  were  also  observed.  The 
cleansed  reservoir  was  dressed  with  lime  and  the  water  again 
turned  in.  All  went  well  until  the  corresponding  week  of 
the  following  year,  when  the  water  from  the  same  set  of 
reservoirs  again  developed  the  fishy  odour  and  flavour. 


QUALITY  OF  DRINKING  WATERS  117 

This  time,  however  it  was  reservoir  B  which  was  chiefly 
affected,  though  the  water  in  C  was  not  destitute  of  odour. 
The  water  in  the  covered  reservoir,  A,  remained  free  from 
algoid  growth  and  was  odourless.  In  C  Chara  was  again 
developing,  whilst  in  B  the  growth  was  abundant.  This, 
Dr.  Garrett  thinks,  proves  conclusively  that  the  Chara  is 
the  cause  of  the  trouble.  It  is  worthy  of  remark,  however, 
that  he  found  Lyngbya  muralis  parasitic  on  this  plant, 
and  that  Dr.  Farlow  of  Harvard  University,  in  the  Bulletin 
of  the  Bussey  Institution  for  1877,  ascribes  a  peculiar 
suffocating  odour  as  being  due  to  the  presence  of  this 
species  of  Nostoc  in  potable  waters.  A  similar  odour,  he 
says,  is  produced  by  other  species  of  Lyngbyce  and  Oscilla- 
torice,  whilst  Beggiatoa  (the  so-called  sewage  fungus)  gives 
off  a  sulphurous  odour,  and  decaying  Nostoc  a  more  disagree- 
able odour  of  pig  or  horse-dung.  Pari  passu  with  the 
development  of  the  fishy  odour  in  the  Cheltenham  water, 
the  amount  of  organic  matter  (as  measured  by  the  organic 
ammonia  and  the  permanganate  required  for  oxidation)  also 
increased  therein,  and  to  distinguish  this  from  pollution 
entering  the  reservoir  from  without,  Dr.  Garrett  calls  it 
"  natural  "  contamination.  The  Cheltenham  water  supply 
is  naturally  very  pure  and  has  a  hardness  of  7  to  11  degrees. 
In  this  latter  respect,  therefore,  it  differs  from  the  other 
waters  which  have  been  mentioned  as  similarly  affected, 
since  all  are  surface  waters  of  the  softest  character.  At 
Gloucester,  however,  which  also  lies  in  the  Severn  valley, 
and  which  is  supplied  with  a  water  from  a  similar  source, 
there  have  been  from  time  to  time  complaints  due  to  the 
same  cause.  Invariably  these  odours  develop  in  the  autumn, 
but  in  certain  years  only,  hence  we  may  reasonably  infer 
that  the  climatic  conditions  have  been  especially  favourable 
for  the  growth  of  the  particular  organism  or  organisms 
which  by  their  metabolic  changes,  or  by  their  degeneration 
or  decay,  give  rise  to  the  foul-smelling  compounds  which 
taint  the  water,  The  drinking  of  such  waters  is  not 


n8  WATER  SUPPLIES 

recorded  to  have  caused  any  illness,  or  any  disagreeable 
effects  beyond  a  sensation  of  nausea.  The  water,  however, 
cannot  be  considered  to  be  wholesome,  and  if  there  is  no 
alternative  supply  it  should  be  well  filtered  and  boiled 
before  use.  Boiling  alone  will,  in  some  cases,  entirely 
remove  the  odour,  whilst  in  others  it  appears  to  accentuate 
it  unless  the  organisms  producing  it  have  been  previously 
removed  by  filtration. 

Small  eels  have  been  found  in  water-mains,  and  these  by 
their  decomposition  have  been  known  to  impart  a  dis- 
agreeable odour  to  the  water  drawn  therefrom.* 

A  recent  case  of  somewhat  similar  character  occurred  in 
a  small  Essex  hamlet  obtaining  its  water  supply  from  a 
pond.  The  water  acquired  a  disgusting  odour  in  the  early 
summer,  and  I  found  that  during  the  previous  winter, 
which  had  been  very  severe,  the  water  had  been  frozen  into 
one  mass  of  ice.  After  the  thaw  a  quantity  of  dead  fish 
had  been  removed,  but  apparently  some  had  remained  in 
the  pond,  and  with  the  advent  of  still  warmer  weather 
these  were  decomposing  rapidly,  and  the  products  of  the 
putrefactive  processes  were  tainting  the  water.  In  another 
case  a  water  flowing  from  a  disused  mine  acquired  a  most 
offensive  odour;  from  the  microscopical  and  chemical 
examination  of  the  water  I  concluded  that  some  animal 
had  fallen  down  the  shaft,  which  was  on  the  hill  above,  and 
had  been  killed,  and  that  its  body  was  decomposing  and 
polluting  the  water.  Dead  animals  (from  mice  to  babies) 
have  been  found  in  cisterns  and  tanks  used  for  storing 
water  when  the  development  of  some  peculiar  flavour  has 
caused  them  to  be  examined.  That  putrid  animal  matters 
often  contain  poisons  of  the  deadliest  character  is  well 
known,  hence  waters  containing  any  products  of  such 
decomposition  should  be  looked  upon  as  especially 
dangerous. 

*"Eels  in  Water-Mains  of  the  East  London  Waterworks,"  Local 
Government  Board  Report,  1887, 


QUALITY  OF  DRINKING   WATERS  119 

Taste. — Smell  and  taste  are  often  confounded,  for  many 
substances  possessing  very  strong  odours,  and  generally 
reputed  to  have  equally  characteristic  and  powerful  tastes, 
are  really  tasteless.  Vanilla,  garlic  and  assafoetida  may  be 
cited  as  examples.  If  the  sense  of  smell  be  lost,  or  be  held 
in  temporary  abeyance  by  closing  the  nostrils,  it  will  be 
found  that  these  substances  are  perfectly  insipid  and 
flavourless.  Doubtless  many  of  the  waters  which  have  just 
been  referred  to  as  having  fishy,  aromatic,  or  other  odours 
and  tastes,  are  really  tasteless.  But  odourless  waters  may 
affect  the  sense  of  taste.  Thus  a  very  small  quantity  of  iron 
gives  water  an  astringent  inky  flavour,  whilst  an  excess  of 
common  salt  makes  the  water  saline  or  brackish.  Rain 
water  has  a  peculiar  flavour,  and  freshly  distilled  water  is 
most  insipid.  Without  having  a  distinct  flavour,  however, 
waters  vary  much  in  palatability.  A  well  -  aerated, 
moderately  hard  water,  such  as  is  derived  from  wells  in  the 
chalk  and  oolite,  and  from  deep  springs,  is  the  most 
palatable.  Upland  surface  waters  and  stored  or  aerated 
rain  waters  are  moderately  palatable,  whilst  fresh  rain 
water  and  most  polluted  waters  are  least  palatable.  Some 
shallow  well  waters  containing  very  large  amounts  of 
oxidised  sewage  matters  are  exceedingly  palatable,  and 
every  analyst  and  medical  officer  can  recall  instances  in 
which  such  waters  have  been  held  in  high  esteem  for  their 
brilliancy,  pleasant  flavour,  and  sparkling  character,  until 
something  has  occurred  which  caused  the  water  to  be 
examined  and  its  true  nature  discovered.  Whilst  a  good 
water,  therefore,  should  be  palatable,  it  does  not  follow  that 
because  a  water  is  very  palatable  that  it  is  also  very  pure 
and  well  adapted  for  domestic  purposes. 

Turbidity. — A  good  drinking  water  should  be  quite 
bright  and  free  from  all  suspended  impurities.  Substances 
in  a  very  minute  state  of  division  render  water  opalescent, 
and  settle  very  slowly,  if  at  all.  Larger  particles  of 
mineral  substances,  living  organisms  visible  to  the  naked 


120  WATER  SUPPLIES 

eye,  and  vegetable  and  animal  debris,  cause  a  greater  or 
less  turbidity  according  to  the  amount  present.  Very  often 
a  water  which  looks  quite  clear  in  an  ordinary  tumbler  is 
found  to  be  opalescent  or  turbid  when  viewed  in  a  tube 
1  or  2  feet  in  depth. 

Insoluble  mineral  matters  usually  deposit  rapidly;  clay, 
however,  causes  a  turbidity  which  disappears  very  slowly 
and  is  sometimes  very  difficult  to  remove  even  by  nitration. 
A  public  water  supply  with  which  I  am  acquainted  was 
always  more  or  less  turbid.  It  was  derived  from  chains  of 
wells  sunk  in  loam  and  sand,  and  after  heavy  rains  the 
amount  of  suspended  clayey  matter  gave  the  water  a  most 
unsightly  appearance.  Many  endeavours  had  been  made 
to  clarify  the  water,  including  treatment  with  alum,  and 
nitration  through  sand,  vertical  sheets  of  flannel,  etc.,  but 
without  ensuring  really  satisfactory  results.  At  my  sug- 
gestion filter  beds  were  constructed  of  polarite  and  sand, 
and  the  water  since  has  been  delivered  to  the  consumers 
in  a  perfectly  clear  and  almost  brilliant  condition. 

The  nature  of  the  suspended  matter  can  often  be  dis- 
tinguished by  the  unaided  eye,  and  the  trained  observer 
may  draw  important  inferences  from  such  an  examination ; 
but  more  frequently  the  aid  of  the  microscope  has  to  be 
invoked  to  determine  the  character  of  the  deposit.  Finely- 
divided  mineral  matter  brought  down  by  rivers  in  flood 
times  is  said  to  be  capable  of  causing  diarrhoea  (vide 
Chap  X.).  Dead  organic  matter,  or  debris,  may  be  derived 
from  decaying  plants  and  animals.  The  presence  of  cotton, 
linen  or  silk  fibre,  of  potato  starch,  spiral  cells  of  cabbage 
and  similar  plants,  fragments  of  paper,  etc.,  indicate  con- 
tamination with  sewage,  and  therefore  that  the  water  is 
of  a  dangerous  character.  Whatever  the  source,  any 
considerable  quantity  of  such  impurities  necessarily  impairs 
the  quality  of  the  water. 

The  varieties  of  living  organisms  found  in  water  are 
innumerable.  Many  are  so  minute  as  to  require  the 


QUALITY  OF  DRINKING  WATERS  121 

highest  powers  of  modern  microscopes  for  their  detection, 
and  their  identification  is  a  matter  of  great  difficulty  and 
ofttimes  impossible.     These  bacteria  are  probably  found  in 
all  natural  waters;   but,  generally  speaking,  the  purer  the 
water  the  smaller  the  number  of  bacteria  it  will  contain. 
The  purest  deep-well  waters  are  almost  certainly  entirely 
devoid  of  bacteria  whilst  held  in   the   pores   of   the   sub- 
terranean rocks  from  which  they  are  derived,  but  as  raised 
to   the   surface    of    the    earth    a   few    of    these    ubiquitous 
organisms  invariably  gain  access  either  from  the  air  or  from 
the  materials  with  which  the  water  conies  in  contact,  and 
then   commence   to   multiply   with   inconceivable   rapidity. 
In   other  waters   the   number   of   bacteria   present   varies, 
roughly  speaking,  with  the  degree  of  pollution,  few  being 
found  in  the  purest  waters,  whilst  a  single  drop  of  sewage- 
polluted  water  may  contain  hundreds  of  thousands  of  them. 
Professor  P.  Frankland,  who  has  made  a  special  study  of 
this  subject,  says  :   "  As  regards  the  nature  of  the  bacteria 
found  in  natural  water,  they  are  for  the  most  part  bacilli, 
micrococci  being  comparatively  rare,  whilst  spirilla  are  not 
unfrequently  discovered,  more  especially  in  impure  waters. 
Upwards    of    200    different    forms    or    species    of    micro- 
organisms have  been  already  found  in  water,  and  although 
by    far   the    majority   of    these    are    presumably    perfectly 
harmless,  a  number  of  well-known  pathogenic  forms  have 
also  been  discovered/'     Amongst  these  are  the  bacillus  of 
typhoid  fever,   of  cholera,  of  tetanus,  of  anthrax,   and  of 
tubercle.     Singularly    enough    these   pathogenic   organisms 
retain   their  vitality  longer  when   introduced   into   sterile 
water  than  when  added  to  a  natural  water  containing  the 
ordinary  water  bacteria.     Exposure  to  sunshine  appears  to 
have    a    most    destructive    effect    upon    all    bacteria,    but 
Professor  Frankland  thinks  "  it  can  only  be  in  very  shallow 
bodies  of  water,  and  in  the  superficial  layers  of  deep  ones, 
that  it  can  exercise  its  power." 

The  minuteness   of   these   organisms   is   such   that   it   is 


122  WATER  SUPPLIES 

probable  that  they  never  occur  even  in  polluted  waters  in 
such  quantities  as  to  render  it  opalescent  to  the  unaided 
eye.  Doubtless  their  presence  would  be  revealed  in  the 
track  of  Professor  TyndalFs  concentrated  ray  of  light,  just 
as  particles  of  dust  are  revealed  by  a  sunbeam. 

The  presence  of  the  spores  and  mycelia  of  the  higher 
fungi  indicates  impurity  probably  derived  from  sewage, 
since  the  latter  invariably  contains  phosphates,  without 
which  these  forms  cannot  live. 

Algae,  diatoms,  and  desmids  are  found  in  open  wells, 
ponds,  lakes,  and  running  streams,  and,  as  we  have  seen, 
some  forms  are  believed  to  be  the  cause  of  the  peculiar 
odours  sometimes  developed  in  practically  stagnant  water. 
Apart  from  this,  their  presence  is  of  little  importance,  more 
especially  as  they  are  easily  removable  by  nitration.  These 
forms  of  vegetable  life  (unlike  most  fungi)  do  not  depend 
upon  decaying  vegetable  and  animal  matter  for  their 
sustenance,  whilst  the  lower  forms  of  animal  life,  next  to 
be  referred  to,  can  only  exist  in  waters  containing  such 
substances,  and  which  therefore  are  more  or  less  impure. 

The  lowest  forms  of  animal  life  are  only  found  in  waters 
containing  organic  matter  in  solution.  This  organic 
material  may,  however,  be  merely  derived  from  decaying 
vegetable  matter,  such  as  is  found  in  the  water  of  bogs  and 
marshes,  but  these,  nevertheless,  cannot  be  considered  as 
wholesome  for  drinking  purposes.  Ciliated  animalculse  also 
abound  in  stagnant  water,  and  Hassall  noticed  that  in  the 
Thames  Paramecia  were  abundant  below  Brentford,  where 
the  river  was  polluted  with  sewage,  whilst  they  were  rare 
higher  up  the  stream  where  the  water  was  comparatively 
pure.  The  higher  forms  of  life  do  not  necessarily  denote 
impurity,  but  the  presence  of  worms  or  of  their  ova  or 
embryos  is  especially  objectionable,  since  these  may  be 
forms  which  can  live  and  develop  in  the  human  system  and 
produce  harmful  effects  (vide  Chapter  IX.).  Eels  have 
been  found  in  water  mains,  and  in  Chicago  lately  snails 


QUALITY  OF  DRINKING   WATERS  123 

(Bythenia  tentacula)  were  found  in  water  which  had  passed 
through  the  mains. 

The  Soluble  Constituents  of  Potable  Waters. — The  sub- 
stances in  solution  may  be  of  mineral  or  of  organic  origin, 
the  former  derived  from  the  rocks  with  which  the  water 
has  been  in  contact,  and  the  latter  from  disintegrating  or 
decomposing  animals  and  plants,  from  manured  soils, 
sewage,  etc. 

Organic  matter  of  any  kind  is  objectionable.  That  which 
is  derived  from  peat  merely  is  least,  that  from  sewage  most, 
obnoxious.  In  passing  through  soil,  however,  organic 
matter  becomes  more  or  less  completely  oxidised, — the 
carbon  into  carbonic  acid  gas,  and  the  nitrogen  into 
ammonia,  nitrous  or  nitric  acid,  the  two  latter  of  which, 
acting  upon  the  carbonate  of  lime  present  in  all  soils,  form 
nitrites  and  nitrates,  liberating  an  additional  amount  of 
carbonic  acid.  This  dissolves  in  the  water,  and  gives  the 
sparkling  character  so  often  observed  in  water  from  shallow 
wells  sunk  in  polluted  subsoils.  This  process  of  purification 
will  be  discussed  more  fully  in  a  later  section,  whilst  the 
significance  of  the  presence  of  ammonia  and  of  nitrites  and 
nitrates  —  substances  which  in  themselves  are  perfectly 
harmless — will  be  better  treated  of  when  the  interpretation 
of  the  results  of  analyses  is  being  considered.  Although 
dissolved  organic  matter  is  objectionable,  it  is  only  when 
present  in  some  quantity,  as  in  water  from  swamps  and 
marshes,  and  water  highly  polluted  with  sewage,  that  the 
organic  matters  themselves  are  likely  to  have  any  baneful 
effects.  Even  sewage-polluted  water  may  be  imbibed  for 
years  without  producing  any  appreciable  effect  upon  the 
health;  but  sooner  or  later  the  specific  poison  of  typhoid 
fever,  cholera,  diarrhoea,  or  other  disease  is  introduced  by 
the  sewage,  and  an  outbreak  almost  inevitably  follows. 
Polluted  waters,  and  the  diseases  which  have  been  attri- 
buted to  their  use,  will  be  considered  in  the  next  chapter. 
The  total  amount  of  saline  matter  permissible  in  a 


i24  WATER  SUPPLIES 

drinking  water  depends  in  a  great  measure  upon  the  nature 
of  the  salts.  No  hard  and  fast  line  can  be*  drawn,  but  the 
best  waters  rarely  contain  more  than  20  grains  of  mineral 
matter  per  gallon.  When  100  grains  is  reached  the  water 
becomes  rather  of  the  character  of  a  "  mineral  "  than  a 
"  potable  "  water.  The  analyses  already  given  show  the 
wide  variation  which  exists  in  the  amount  of  inorganic 
matter  contained  in  water  used  for  public  supplies,  both 
when  obtained  from  similar  and  from  diverse  sources.  Thus 
the  exceedingly  pure  lake  water  supplied  to  Glasgow 
contains  less  than  5  grains  of  solid  matter  per  gallon,  whilst 
the  equally  pure  water  supplied  from  deep  chalk  wells  to 
many  towns  in  Essex  contains  from  70  to  100  grains  of 
saline  matter  per  gallon.  These  deep-well  waters,  like  many 
others  derived  from  more  superficial  sources  near  the  coast 
or  the  banks  of  tidal  rivers,  contain  a  considerable  amount 
of  common  salt,  but  where  the  amount  is  not  sufficient  to 
more  than  suggest  the  presence  of  this  ingredient  to  the 
taste  (about  50  grains  per  gallon)  it  appears  to  be  quite 
harmless.  More  than  this  would  probably  not  be  tolerated, 
though  it  might  be  exceedingly  difficult  to  prove  that  it 
was  otherwise  obnoxious. 

These  saline  deep-well  waters  also  contain  much  car- 
bonate of  soda,  in  certain  cases  sufficient  to  exert  a 
prejudicial  effect  upon  plants  when  used  for  watering 
purposes,  yet  apparently  without  the  slightest  influence 
upon  the  human  organism. 

With  reference  to  the  alleged  influence  of  the  hardness 
of  water  upon  health,  the  Rivers  Pollution  Commission, 
the  Royal  Commission  on  Water  Supply,  and  other  Com- 
missions, received  and  considered  a  large  mass  of  evidence. 
A  commission  appointed  in  1851  to  consider  the  London 
water  supply,  reported  that  "  an  aerated  water  is  manufac- 
tured and  safely  consumed  to  some  extent,  which  contains 
92  grains  of  carbonate  of  lime  per  gallon,  instead  of  12  or 
14  grains,  as  in  Thames  water.  The  portion  of  lime  and 


QUALITY  OF  DRINKING  WATERS  125 

hiagnesian  salts  in  the  water  drunk  must  indeed  be  greatly 
exceeded  in  general  by  the  quantity  of  the  same  salts  which 
enters  the  system  in  solid  food.  The  only  observations 
from  which  an  inference  of  the  lime  in  water  in  deranging 
the  processes  of  digestion  and  assimilation  in  susceptible 
constitutions  has  been  conjecturally  inferred,  have  been 
made  upon  waters  containing  much  sulphate  of  lime  and 
magnesia,  as  shallow-well  water,  or  the  hard  selenitic  water 
of  the  new  red  sandstone,  and  have  no  force  as  applied  to 
the  Thames  and  its  kindred  waters,  as  the  earths  exist  in 
these  principally  in  the  form  of  carbonate."  A  French 
Commission  reported  that  the  evidence  received  tended  to 
prove  that  in  hard  water  districts  the  inhabitants  had  a 
better  physique  than  in  the  soft  water  districts;  and  a 
Vienna  Commission  reported  in  favour  of  a  moderately  hard 
water  for  a  similar  reason.  The  Rivers  Pollution  Com- 
missioners prepared  tables  of  death-rates  of  a  large  number 
of  towns  divided  into  three  groups  :  (1)  those  supplied  with 
soft  water ;  (2)  those  supplied  with  moderately  hard  water ; 
and  (3)  those  supplied  with  hard  water,  and  concluded 
that,  "  Where  the  chief  sanitary  conditions  prevail  with 
tolerable  uniformity,  the  rate  of  mortality  is  practically 
uninfluenced  by  the  softness  or  hardness  of  the  water 
supplied  to  the  different  towns;  and  the  average  rate  of 
mortality  in  the  different  water  divisions  varies  far  less 
than  the  actual  mortality  in  the  different  towns  of  the  same 
division."  The  evidence  received  by  this  commission  also 
showed  that  in  the  British  Islands  the  tallest  and  most 
stalwart  men  were  found  in  Cumberland  and  the  Scotch 
Highlands,  where  the  water  used  is  almost  invariably  very 
soft.  It  appears  to  be  impossible  to  prove  that,  so  far  as 
health  is  concerned,  either  soft  or  hard  water  has  the 
advantage ;  but  there  is  a  general  consensus  of  medical 
opinion  in  favour  of  soft  water.  The  opinion  so  often 
expressed  that  hard  waters  tend  to  produce  gravel  and 
calculus  appears  to  have  no  foundation  in  fact — at  least  no 


126  WATER  SUPPLIES 

proof  of  such  affections  being  more  common  in  hard  water 
districts  than  in  soft  has  ever  been  forthcoming.  That 
hard  water  tends  to  produce  digestive  derangements  is 
believed  by  many  medical  practitioners!,  but  my  own 
impression  is  that  such  derangements,  if  they  ever  occur 
from  this  cause,  are  only  temporary,  and  are  induced  in 
those  who,  having  been  long  accustomed  to  the  use  of  soft 
water,  for  some  reason  have  changed  to  a  hard  water.  After 
such  a  change  it  is  conceivable  that  the  system  may  take 
time  to  accommodate  itself  to  the  altered  circumstances. 
In  an  article  in  The  Asclepiad,  Sir  B.  Ward  Richard- 
son refers  to  the  use  of  hard  water  in  certain  fashionable 
watering-places,  and  attributes  to  it  an  injurious  effect 
upon  the  health  of  the  visitors.  The  first  few  days  of  quiet 
and  change  produce  a  beneficial  effect,  then  dyspeptic 
symptoms  set  in — flatness,  constipation,  pain  in  the 
stomach,  sleeplessness,  etc. ;  the  person  then  becomes  low- 
spirited  and  possibly  somewhat  hysterical,  the  kidneys  get 
out  of  order,  and  much  pale-coloured  urine  is  passed.  All 
these  symptoms,  Dr.  Richardson  believes,  in  nine  cases  out 
of  ten,  are  due  to  the  hardness  of  the  water  and  nothing 
else.  That  hard  water  is  superior  to  soft  on  account  of  its 
greater  palatability  is  probably  also  a  fallacy.  The 
palatability  depends  more  upon  the  degree  of  aeration,  and 
as  a  rule  hard  natural  waters  are  better  aerated  than  soft 
waters.  The  insoluble  lime  soap  formed  when  washing  in 
hard  water  is  difficult  to  remove  from  the  pores  of  the  skin, 
and  it  causes,  more  especially  in  those  not  accustomed  to 
its  use,  an  unpleasant  sensation,  as  though  the  skin  were 
not  thoroughly  clean,  and  may  cause  a  roughness  of  the 
cuticle  and  affect  the  complexion.  It  has  even  been 
suggested  that  the  insoluble  soap  or  curd,  by  clogging  the 
pores  or  outlets  of  the  sweat  glands,  interferes  with  the 
proper  discharge  of  the  functions  of  these  glands  and  gives 
rise  to  pimples.  By  horse  trainers  soft  water  is  preferred, 
hard  water  being  credited  with  producing  a  "  staring " 
coat,  which  is  certainly  not  indicative  of  perfect  health. 


QUALITY  OF  DRINKING  WATERS  127 

For  washing  purposes  the  superiority  of  soft  water  is 
undoubted.  Apart  from  the  use  of  soap,  the  detergent 
qualities  of  a  water  containing  very  little  calcareous  matter 
in  solution  are  more  marked  than  in  waters  containing  a 
large  proportion  of  such  substances;  but  when  soap  is 
used,  all  the  latter  have  to  be  removed  before  the  soap 
dissolves  in  the  water,  and  so  a  certain  amount  is  wasted. 
The  first  action  of  the  soap  is  to  soften  the  water,  and  this 
is  a  very  expensive  method.  The  insoluble  curd  produced 
adheres  to  the  articles  being  washed,  and  requires 
additional  time  and  labour  and  soap  to  remove  it.  Where 
a  hard  water  only  is  available  for  a  public  supply  it  is  much 
cheaper,  as  we  shall  see  in  the  sequel,  to  soften  the  water  by 
the  use  of  certain  chemicals  before  supplying  it  to  the 
consumers. 

For  other  domestic  purposes  also  soft  water  possesses 
many  advantages.  Before  a  Koyal  Commission  Dr.  Holland 
stated  that  soft  water  extracted  the  strength  of  tea  twice 
as  well  as  hard;  and  Professor  Clark  gave  the  opinion 
that,  as  the  result  of  his  experiments,  hard  water  was  quite 
unfitted  for  making  tea.  Too  much  stress,  however,  cannot 
be  laid  on  this  evidence,  since  the  increased  solvent  power 
of  soft  water  is  mainly  upon  the  tannin  and  astringent 
principles,  the  most  objectionable  constituents  of  the  tea- 
leaf,  and  waters  whose  hardness  is  due  to  the  presence  of 
carbonates,  become  much  softer  when  well  boiled  from  the 
deposition  of  the  lime  salts  as  a  fur  upon  the  sides  of  the 
kettle.  Monsieur  Soyer,  the  famous  cook,  said  that  hard 
water  gave  cabbages,  greens,  spinach,  asparagus,  and 
especially  French  beans,  a  yellow  tinge,  and  that  the  boiling 
process  had  to  be  prolonged,  entailing  an  additional 
expenditure  for  fuel.  For  boiling  meat  or  making  soup 
it  was  not  so  good  as  soft  water,  the  latter  appearing  to 
open  the  pores  of  the  meat,  whilst  hard  water  compressed 
them.  Soft  water  extracted  the  flavour  of  both  vegetables 
and  meat,  and  the  juice  or  gravy  of  the  latter  much  better 


I28  WATER  SUPPLIES 

than  hard  water.  Soft  water  evaporated  one-third  faster 
than  hard  water.  For  cooking  purposes  he  would  in  every 
way  "  give  the  preference  to  soft  water/'  The  furring  of 
kettles  and 'boilers  is  also  an  objection  to  the  use  of  hard 
water.  A  furred  vessel  requires  more  heat,  and  therefore 
increases  the  amount  of  fuel  used  and  of  time  required  to 
raise  the  water  to  any  given  temperature.  The  metal  of 
which  the  vessel  is  composed  gets  unnecessarily  hot,  and  if 
at  such  a  time  the  fur  should  crack  and  the  water  come  in 
contact  with  the  superheated  metal,  it  may  determine  a 
fracture.  In  boilers  used  for  working  engines  by  steam 
such  an  accident  has  often  caused  an  explosion.  For  such 
purposes,  therefore,  hard  water  is  very  unsuitable. 

But  are  there  no  objections  to  be  urged  on  the  other  side 
to  the  use  of  soft  water  for  domestic  purposes?  With  one 
exception  there  is  apparently  no  disadvantage  in  the  use  of 
the  softest  of  waters.  The  exception  is  the  proneness  of 
certain  soft  waters  to  act  upon  metals,  to  dissolve  lead  and 
zinc,  and  to  corrode  iron  pipes.  This  subject  will  be  again 
referred  to  in  Chapter  IX.,  and  when  treating  of  storage 
cisterns,  mains,  and  service  pipes.  The  objection  only 
applies  to  waters  with  a  temporary  hardness  of  less  than 
2  or  3  degrees;  but  such  waters  are  at  the  present  time 
being  supplied  to  enormous  populations,  and  the  extent  of 
its  deleterious  effect  upon  the  consumers  is  only  just 
beginning  to  be  realised. 

To  sum  up  :  The  ideal  of  a  potable  water  is  one  which  is 
colourless  and  odourless,  and  which  is  free  from  all  organic 
matter,  and  from  all  but  the  merest  trace  of  the  products 
of  the  oxidation  of  such  matter,  and  which,  while  containing 
just  sufficient  carbonate  of  lime  to  prevent  action  upon 
metals,  contains  but  little  of  any  other  saline  constituent. 
That  whilst  a  small  amount  of  organic  matter,  if  of  peaty 
origin,  is  not  very  objectionable,  the  slightest  trace  of 
unoxidised  sewage  is  an  indication  that  the  water  is 
dangerous.  That  for  all  domestic  and  manufacturing 


QUALITY  OF  DRINKING   WATERS  129 

purposes  a. soft  water  is  preferable  to  a  hard  water.  That 
a  hard  water,  in  which  the  hardness  is  chiefly  due  to  the 
presence  of  carbonates, — that  is,  in  which  the  hardness  is 
chiefly  temporary — is  preferable  to  a  water  which  is  per- 
manently hard  from  the  presence  of  sulphates.  That  hard 
waters,  in  which  the  hardness  is  due  to  the  presence  of 
magnesian  salts  (the  sulphate  more  especially),  are  more 
objectionable  than  those  in  which  the  hardness  is  due  to 
lime  salts.  That  deep-well  waters  containing  a  moderate 
amount  of  common  salt  and  of  carbonate  of  soda,  appear  to 
be  quite  free  from  objection  for  domestic  purposes.  It 
should,  however,  be  added  that  such  waters,  especially  if 
they  contain  chloride  of  magnesium,  as  they  usually  do, 
injuriously  affect  "  boilers,"  causing  them  to  leak  at  the 
rivets  and  corroding  the  taps,  so  entailing  expense  in  repairs 
and  shortening  the  life  of  the  apparatus.  For  this  use, 
therefore,  they  are  not  to  be  commended. 

The  following  recent  analyses,  made  in  my  laboratories, 
show  the  saline  constituents  of  pure  waters  from  a  diversity 
of  geological  sources.  Those  given  are  selected  as  being 
more  or  less  typical,  but  it  must  be  remembered  that 
considerable  variations  occur.  All  results  are  expressed  in 
parts  per  100,000. 


1.  Chalk,  Exposed  :— 

Calcium  carbonate         .        „        .        *        .  16'0 
Calcium  sulphate  .        »        ;        . ,.   '.  ••''•+'•      2-4 

Calcium  nitrate 2'15 

Calcium  chloride  .         .         .         .  .          0-55 

Magnesium  chloride 0*6 

Sodium  chloride 2-0 

Silica,  etc 1-3 

Total  25-0 


WATER  SUPPLIES 


2.  Chalk,  beneath  London  Clay : — 

Calcium  carbonate 
Magnesium  carbonate    . 
Sodium  carbonate 
Sodium  sulphate    . 
Sodium  chloride    . 
Potassium  nitrate 
Silica,  etc 


Total 


1-9 
1-4 

23-3 
8-6 

52-95 
0-25 
1-6 

90-0 


3.  Thanet  Sands,  underlying  the  London  Clay : — 

Calcium  carbonate 

Magnesium  carbonate 

Sodium  carbonate 

Sodium  sulphate 

Sodium  chloride 

Silica,  etc. 


Total 


2-0 

1-55 

28-0 

18-35 

25-6 

1-5 

77-0 


4.  New  Red  Sandstone : — 

Calcium  carbonate 
Magnesium  sulphate 
Magnesium  chloride 
Sodium  nitrate 
Silica,  etc. 


Total 


6-6 

3-0 

1-8 

3-95 

1-15 

16-5 


5.  Lower  Greensand : — 

Calcium  carbonate 
Calcium  sulphate 
Magnesium  chloride 
Sodium  chloride    . 
Sodium  nitrate 
Silica,  etc.      .        . 


9-3 

1-65 

1-0 

0-75 

1-25 

1-55 


Total 


15-5 


QUALITY  OF  DRINKING  WATERS  131 

6.  Ashdown  Sands: — 

Calcium  carbonate 7-9 

Magnesium  carbonate 2-1 

Ferrous  carbonate 0'4 

Sodium  sulphate 4-85 

Sodium  chloride 6'1 

Sodium  nitrate 0-8 

Total  22-15 


7.  River  Dee  Water : — 

Calcium  carbonate 8'5 

Magnesium  carbonate 0'4 

Magnesium  sulphate 3 '4 

Sodium  sulphate 1'6 

Sodium  chloride 3*6 

Silica,  etc 1-0 

Total  18-5 


8.  Magnesian  Limestone : — 

Calcium  carbonate 
Magnesium  carbonate 
Sodium  carbonate 
Sodium  sulphate    . 
Sodium  chloride     . 
Potassium  nitrate 
Silica,  etc.      . 


Total        .        .        V        25-5 


9,  Moorland  Surface  Water : — 

Calcium  carbonate         .         . ....        .  0'5 

Calcium  sulphate  .         .         .  •*     ,  •&  1-15 

Magnesium  chloride 0'5 

Sodium  chloride 0-7 

,Sjlica,  organic  matiter,  etc 1-35 

Total  4-2 


132  WATER  SUPPLIES 

10.  Subsoil  Water — Gravel : — 

Calcium  carbonate 17'2 

Magnesium  sulphate     .         .         .         .         .  4-0 

Calcium  sulphate 5-8 

Sodium  chloride 6-1 

Sodium  and  potassium  nitrate       .         .         .  1*7 

Silica,  etc 2-2 

Total         ...       .         .  37-0 

• 

11.  Subsoil  Water — Loamy  Soil : — 

Calcium  carbonate         .....  23'4 

Calcium  sulphate 17 '6 

Calcium  chloride 14-1 

Magnesium  chloride 11-5 

Sodium  chloride 24 -6 

Potassium  nitrate 3-7 

Silica,  etc 3-1 

Total  98-0 


The  following  is  an  example  of  an  impure  water 

12.  Subsoil  Water — Gravel — Surface  highly  manured : — 

Calcium  carbonate 14-0 

Calcium  sulphate 31-3 

Magnesium  sulphate 5-5 

Magnesium  chloride 7 '5 

Sodium  chloride 17 '5 

Potassium  nitrate 22'8 

Sodium  nitrate 17'0 

Organic  matter,  silica,  etc 4-7 

Total         .  •  120-3 


CHAPTER  IX. 

IMPURE  WATER  AND  ITS  EFFECT  UPON  HEALTH. 

A  HYGIENICALLY  pure  water  has  already  been  defined  as 
one  in  which  the  inorganic  and  organic  substances  present 
are  so  small  in  amount  as  not  appreciably  to  affect  its 
physical  properties,  or  render  it  unfit  for  domestic  purposes. 
Accepting  this  definition,  it  is  obvious  that  there  is  no  sharp 
line  of  demarcation  between  the  pure  and  impure.  Often 
the  difference  is  one  of  quantity  rather  than  of  quality, 
and,  as  will  be  found  when  the  interpretation  to  be  put 
upon  the  results  of  chemical  and  bacteriological  examina- 
tions are  being  considered,  opinions  often  differ  as  to  what 
should  be  considered  as  pure  and  safe,  and  as  impure  and 
unsafe.  Even  waters  which  are  merely  hard,  but  otherwise 
of  excellent  quality,  are,  as  we  have  seen,  strongly  suspected 
to  cause  dyspeptic  symptoms  in  certain  individuals,  more 
especially  if  not  previously  accustomed  to  their  use.  The 
effects  produced  upon  health  by  impurities  of  mineral  origin 
differ  from  those  produced  by  living  organisms  which  are 
capable  of  multiplying  within  the  system  and  causing 
specific  disease.  Dead  organic  matter  appears  often  to  be 
innocuous  in  itself,  but  is  believed  to  cause  diarrhoea 
occasionally.  As  this  affection  is  also  often  produced  both 
by  soluble  and  insoluble  mineral  impurities,  it  may 
appropriately  be  considered  first. 

Diarrhoea. — A  water  containing  an  excess  of  magnesium, 
calcium  or  sodium  sulphate,  or  of  magnesium  chloride,  will 
be  more  or  less  aperient  in  its  action,  the  effect  depending 

(133) 


134  WATER  SUPPLIES 

in  part  upon  the  amount  of  the  salts  present,  and  in  part 
upon  the  constitution,  etc.,  of  the  person  drinking  it.  Finely- 
divided  mineral  matter — such  as  clay,  scales  of  mica,  etc., 
often  found  in  turbid  river  water — has  been  repeatedly 
known  to  cause  diarrhoea,  probably  by  irritation  of  the 
mucous  membrane  lining  the  alimentary  canal.  Suspended 
vegetable  debris  has  also  been  credited  with  producing  the 
same  effect.  Pond  water  containing  much  vegetable  matter 
(infusion  of  dead  leaves,  algae,  etc.),  is  well  known  to  have 
a  tendency  to  produce  diarrhoea,  especially  amongst 
families  who  have  not  previously  drunk  such  water.  Sewage- 
polluted  water  has  frequently  caused  outbreaks  of  this 
disease — sometimes  with  decided  choleraic  symptoms.  These 
outbreaks,  however,  must  be  distinguished  from  those  of 
true  cholera,  which  can  only  be  induced  by  specific  pollu- 
tion. The  autumnal  diarrhoea  so  prevalent  in  certain 
districts  appears  to  have  little,  if  any,  connection  with  the 
water  supply;  but  it  has  been  asserted  that  water  stored 
in  reservoirs  or  cisterns  during  hot  weather  has  a  tendency 
to  cause  diarrhoea,  especially  if  the  temperature  of  the 
water  reaches  60°  F. 

The  various  ways  in  which  water  may  be  polluted  and 
cause  diarrhoea  are  exemplified  in  the  following  cases, 
selected  out  of  many  found  recorded  in  the  reports  of 
medical  officers  of  health,  in  medical  journals  and  else- 
where :  — 

During  the  Mexican  War  (1861-62)  the  French  troops, 
when  at  Orizaba,  were  compelled  to  drink  water  impreg- 
nated with  sulphuretted  hydrogen,  and  suffered  from 
diarrhoea  and  flatulency;  the  eructated  gases  had  the 
offensive  odour  of  rotten  eggs. 

At  Salford  Gaol,  some  years  ago,  an  outbreak  of  diarrhoea 
occurred  amongst  the  prisoners  using  water  which  passed 
through  a  certain  tank.  The  warders,  who  used  water  from 
the  same  source,  but  which  had  not  been  stored  in  the  tank, 
were  not  affected ;  and  when  the  prisoners  were  supplied 


IMPURE   WATER,  ITS  EFFECT  UPON  HEALTH       135 

with  the  same  water  as  the  warders,  the  diarrhoea  ceased. 
Upon  investigation  it  was  found  that  a  pipe  terminating 
immediately  over  the  surface  of  the  water  in  the  tank  was 
in  direct  communication  with  a  drain.  Probably,  therefore, 
the  water  had  absorbed  drain  air,  and  possibly  micro- 
organisms, and  so  become  polluted. 

Early  in  1891  an  epidemic  of  diarrhoea  occurred  at 
Lincoln.  The  symptoms  were  severe,  but  in  no  case  fatal. 
Dr.  Harrison,  the  Medical  Officer  of  Health,  says  in  his 
report :  "I  consider  it  was  due  to  the  contaminated  state 
of  the  drinking  water.  The  disease  attacked  people  in 
Lincoln,  Bracebridge,  and  the  County  Asylum,  where,  out 
of  750  inmates,  73  suffered.  ...  In  Upper  Bracebridge, 
within  50  yards  of  the  asylum,  no  case  of  diarrhoea  was 
reported.  These  people  were  exposed  to  the  extreme  cold, 
but  had  a  different  water  supply.  At  the  time  of  the 
outbreak  the  supply  was  chiefly  from  the  river  Witham, 
which  had  for  some  weeks  been  frozen.  The  water  was 
turbid,  and  had  an  offensive  smell  when  heated,  and 
contained  a  large  excess  of  organic  matter." 

At  Sedgley  Park  School  in  1874  the  contamination  of  the 
water  supply  by  ordinary  sewage  was  followed  by  an 
outbreak  of  diarrhoea  and  sickness,  associated  with  great 
languor  and  prostration.  The  defective  drain  was  repaired 
and  the  attacks  ceased. 

In  a  large  factory  in  Schenectady,  New  York,  employing 
2,000  hands,  much  inconvenience  was  felt,  independent  of 
season,  from  prevalence  of  diarrhoeal  diseases  amongst 
workmen,  sometimes  10  per  cent,  of  the  employe's  being 
affected.  The  company  substituted  distilled  water  for  that 
from  the  river  Mohawk,  allowing  no  other  in  the  works. 
The  improvement  in  the  health  of  the  hands  was  so  marked 
that  arrangements  are  being  made  to  supply  the  families  of 
the  operatives  as  well,  and  another  firm  is  about  to  adopt 
the  same  practice.  (Thirteenth  Report,  State  Board  of 
Health  of  New  York,  p.  514). 


136  WATER  SUPPLIES 

Diarrhoea  of  a  dysenteric  character,  or  possibly  true 
dysentery,  may  also  result  from  the  use  of  impure  water. 
Many  outbreaks  have  been  described  by  medical  officers  on 
service  in  tropical  countries,  some  traced  to  suspended 
matters  brought  down  by  floods,  others  to  the  fouling  of 
the  water  by  cesspit  oozings  and  fsecal  soakage,  others  to 
water  collected  from  near  where  a  large  number  of  bodies 
had  been  interred,  and  still  others  to  the  use  of  water 
which  appeared  only  to  be  brackish.  In  many  cases,  when 
a  purer  supply  of  water  was  obtained,  the  epidemic  ceased. 
Thus  in  1870  a  severe  epidemic  of  dysentery  occurred 
amongst  certain  of  the  troops  at  Metz  who  used  water  from 
wells  which  were  found  to  be  polluted  with  faecal  soakage. 
These  wells  were  closed  and  the  epidemic  came  to  an  end. 
In  1881  the  wells  were  again  used  for  supplying  drinking 
water  to  the  garrison,  whereupon  the  disease  once  more 
broke  out,  but  disappeared  directly  when  the  wells  were 
again  closed.  At  Prague,  in  1862,  an  outbreak  of  dysenteric 
diarrhoea  followed  the  pollution  of  the  shallow  wells  by  an 
overflow  from  the  sewers.  In  1840  and  1845  Dr.  Hall 
observed  that  dysentery  became  epidemic  in  Tasmania 
amongst  the  population  drinking  stagnant  water,  whilst 
the  convicts  and  others  who  used  pure  well  waters  entirely 
escaped.  Many  instances  are  also  recorded  in  which  the 
water  from  running  streams  was  drunk  with  impunity, 
whilst  that  from  the  standing  pools  caused  diarrhoea. 

Outbreaks  of  dysentery  occurred  at  Millbank  Prison 
(London)  in  1823  and  1824,  which  Dr.  Latham,  after  a  most 
exhaustive  inquiry,  attributed  chiefly  to  the  use  of  a 
polluted  water  supply.*  More  recently  (June,  1894)  Dr. 
George  Turner  has  investigated  the  cause  of  similar  out- 
breaks at  the  Suffolk  County  Asylum  at  Melton.  He  says  : 
"  The  various  forms  of  dysentery  usually  arise  from  the  use 
of  polluted  water  or  decomposed  food,  the  deleterious  action 

*  New  Sydenham  Society  Works  of  Dr.  P.  M.  Latham,  vol.  ii. 


IMPURE  WATER,  tTS  EFFECT  UPON  HEALTH       137 

of  these  two  causes  being  frequently  assisted  and  intensified 
by  bad  hygienic  conditions,  such  as  insufficient  nourishment, 
defective  drainage,  want  of  proper  ventilation,  etc.  ...  In 
fact  the  use  of  bad  water  is  by  far  the  most  common  origin 
of  dysentery,  and  I  have  no  doubt  whatever,  occasioned  the 
late  outbreak.  Probably  former  epidemics  were  due  to  a 
similar  cause."  This  interesting  report  will  be  again 
referred  to.  The  water  was  derived  from  two  deep  bored 
wells  which  had  been  most  carefully  constructed,  and 
which  yielded  a  water  believed  to  be  of  the  highest  degree 
of  purity.  Yet  Dr.  Turner  was  able  to  prove  that  the  water 
in  the  bores  was  polluted  by  leakage,  and  to  this  pollution 
by  subsoil  water  the  periodical  epidemics  were  to  be 
attributed.  As  all  the  sanitary  arrangements,  including 
the  drainage,  were  in  a  very  satisfactory  condition,  the 
subsoil  water  could  not  be  fouled  by  soakage  from  cesspools 
or  defective  drains,  but  that  it  was  specifically  infected 
seems  proved  by  the  report.  One  form  of  dysentery,  at 
least,  is  due  to  the  action  of  an  animal  known  as  the 
"  amoeba  coli,"  and  it  is  interesting  to  note  that  Dr.  Turner 
found  an  amoeba  both  in  the  Drinking  water  and  in  the 
water  of  the  subsoil  through  which  the  bore-tubes  passed. 
The  recent  researches  of  Professor  Klein  seem  to  indicate 
that  the  Bacillus  enteritidis  sporogenes,  found  in  all  sewage, 
and  therefore  in  sewage-polluted  water,  may  be  the  cause 
of  certain  outbreaks  of  epidemic  diarrhoea. 

Diseases  caused  by  the  Mineral  Constituents. 

Goitre. — That  enlargement  of  the  thyroid  gland  may  be 
caused  by  drinking  certain  waters  is  a  well-known  fact,  and 
it  seems  probable  that  this  effect  is  produced  by  some  one 
or  more  of  the  minerals  dissolved  in  it;  but  unfortunately 
we  do  not  know  the  nature  of  the  goitre-producing  sub- 
stance, and  it  is  impossible  therefore  to  ascertain 
beforehand  whether  a  given  water  will  cause  the  disease  or 


138  WATER  SUPPLIES 

not.  In  England  goitre  is  or  was  most  prevalent  in  parts 
of  Derbyshire  and  Nottinghamshire,  and  also  in  the  valleys 
of  Sussex  and  Hampshire.  In  nearly  all  countries  there  are 
localised  areas  in  which  the  affection  appears  to  be  endemic, 
and  it  has  usually  been  noted  that  the  waters  of  such 
districts  contained  much  lime  and  magnesia  salts.  Thus  at 
Kamaon,  in  the  province  of  Oude  (N.W.  India),  Dr. 
M'Clellan  found  that  of  the  population  drinking  water 
collected  from  granite,  gneiss,  and  green  sandstone,  not  one 
was  affected  with  goitre ;  of  those  obtaining  water  from 
clay,  slate,  mica,  and  hornblende,  under  half  per  cent,  were 
affected,  whilst  one-third  of  the  whole  population  deriving 
their  water  supply  from  the  limestone  rocks  suffered  from 
a  more  or  less  severe  form  of  the  disease.  Dr.  Wilson,  on 
the  other  hand,  found  that  at  Bhagsoo  goitre  was  very 
prevalent,  yet  the  waters  here  are  very  soft,  and  almost  free 
from  lime  and  magnesia  compounds.  Other  constituents, 
such  as  sulphide  of  iron,  copper,  etc.,  have  been  sus- 
pected to  be  the  cause  of  goitre,  because  in  certain 
districts  where  the  disease  prevailed  such  impurities 
were  present,  but  observers  have  not  been  slow  to 
point  out  that  such  explanations  are  not  generally  appli- 
cable. That  the  disease  is  really  attributable  to>  the  water 
and  not  merely  to  the  influence  of  soil,  site,  etc.,  appears 
to  be  fully  established.  A  French  Commission  sitting  in 
1873  reported  that  at  Bozel  in  1848  there  was  a  population 
of  1,472,  of  whom  900  were  goitrous,  whilst  at  St.  Bon,  a 
village  some  2,600  feet  higher,  there  was  not  a  single  case. 
When  the  water  supply  of  St.  Bon  was  laid  on  to  Bozel,  the 
disease  decreased  so  rapidly  that  in  1864  there  were  only 
39  people  in  the  latter  village  found  to  be  suffering  there- 
from. In  the  French  military  journals  there  are  many  cases 
quoted,  proving  that  certain  waters  will  produce  goitre  in  a 
few  days,  and  that  persons  were  in  the  habit  of  resorting 
to  the  use  of  these  waters  to  escape  conscription.  On  the 
other  hand  it  has  been  pointed  out  that  in  certain  villages 


IMPURE   WATER,  ITS  EFFECT  UPON  HEALTH       133 

supplied  with  water  from  the  same  source,  some  were 
afflicted  with  goitre,  whilst  others  were  not.  Hirsch,  in 
summing  up  all  the  evidence  as  to  the  cause  and  distribu- 
tion of  the  disease,  says :  "  As  to  the  nature  of  this  goitrous 
virus  and  its  means  of  conveyance,  it  is  impossible  to  form 
a  well-grounded  opinion.  Its  existence  and  development 
would  appear  to  depend  upon  certain  definite  kinds  of  soil, 
such  as  a  soil  containing  dolomitic  rock,  and  it  would  appear 
to  occur  principally  in  water.  Whether  its  nature  is 
organic  or  inorganic  is  a  question  that  evades  our 
answering/7 

Plumbum. — Natural  waters  rarely  contain  lead,  and 
probably  never  in  sufficient  quantity  to  produce  any  evil 
effects;  but  certain  waters,  both  hard  and  soft,  containing 
very  little  or  no  alkaline  carbonates,  dissolve  traces  of  the 
metal  if  conveyed  through  leaden  service  pipes.  The 
amount  of  lead  dissolved  depends  upon  the  character  of  the 
water,  the  time  during  which  it  is  in  contact  with  the 
pipe,  the  temperature,  pressure,  and  possibly  upon  other 
factors  of  which  we  as  yet  know  but  little.  The  effects  pro- 
duced by  the  small  amount  of  lead  dissolved  are  rarely  so 
serious  as  to  cause  death,  or  even  the  severe  colic  or  para- 
lysis characteristic  of  lead  poisoning,  and  for  this  reason  the 
injurious  results  of  the  long-continued  use  of  waters  so 
polluted  are  only  gradually  receiving  recognition.  Amongst 
the  effects  produced  are  a  state  of  listlessness,  leading  to 
melancholia,  depression,  and  actual  insanity,  pallor  and 
debility,  constipation  and  indigestion,  paralysis,  colic,  gout, 
kidney  disease,  blindness,  etc.  Still-births  increase,  and  the 
children  of  lead-poisoned  parents  are  rickety  and  ill- 
developed.  That  the  effects  are  much  more  serious  and 
widespread  than  is  generally  supposed,  is  being  rendered 
evident  by  the  reports  of  the  medical  officers  of  districts 
in  which  such  waters  are  used.  Thus  Dr.  Hunter,  the 
Medical  Officer  of  Health  for  Pudsey  (Yorkshire)  says  in 
his  report  for  1891  :  "  Lead  poisoning  has  been  common  in 


140  WATER  SUPPLIES 

the  town  during  the  year.  This  is  a  matter  that,  from  its 
importance,  claims  your  serious  attention.  As  lead  poison- 
ing is  not  often  registered  as  a  primary  cause  of  death,  it 
does  not  make  a  show  in  the  death-list,  but  there  is  no 
doubt  that  the  death-rate  is  greatly  increased  by  its 
prevalence  in  the  town,  the  deaths  being  registered  as 
caused  by  diseases  of  the  various  organs  of  the  body  that 
have  been  affected  by  the  lead.  But  if  even  no  death  could 
be  put  down  to  lead  poisoning,  the  amount  of  pain, 
suffering,  and  misery  caused  is  widespread,  and  can  only  be 
appreciated  by  the  sufferers.  There  is  a  mistaken  feeling 
amongst  those  who  are  lucky  enough  to  escape,  that  the 
risks  of  this  kind  of  poisoning  are  exaggerated/'  Dr. 
Hunter  found  in  the  water  first  drawn  from  the  taps  in  the 
morning  from  .2  to  1.3  grains  of  lead  per  gallon.  Soon  after 
the  report  appeared,  the  Bradford  Corporation,  who  have 
control  of  the  water  supply,  began  to  add  3  grains  of  chalk 
to  each  gallon,  and  have  continued  so  to  do<  ever  since.  The 
result  has  been  that  no  case  of  lead  poisoning  has  been 
recorded  for  several  years.  Dr.  Barry,  of  the  Local  Govern- 
ment Board,  estimates  that  in  the  West  Riding  of  Yorkshire 
alone  600,000  persons  are  liable  to  lead  poisoning  by  the 
drinking  waters  with  which  they  are  supplied. 

Water  which  has  stood  in  the  pipes  all  night  naturally 
becomes  most  seriously  contaminated,  and  probably,  wer"e 
the  users  careful  to  allow  this  to  run  to  waste  before 
drawing  any  for  drinking  purposes,  cases  of  lead  poisoning 
would  be  less  common.  The  water  which  afterwards  passes 
through  the  pipes  will  contain  an  exceedingly  slight  trace, 
unless  a  great  length  has  to  be  traversed.  Such  waters  will 
of  course  take  up  the  metal  if  stored  in  lead  cisterns,  or  if 
drawn  from  a  well  through  a  leaden  pipe.  The  quantity  of 
lead  necessary  to  produce  any  ill  effect  varies  in  different 
individuals.  The  great  majority  appear  to  be  able  to 
eliminate  the  poison  as  fast  as  it  is  introduced,  but  in 
others  it  tends  to  accumulate  until  the  amount  stored  in 


IMPURE   WATER,  ITS  EFFECT  UPON  HEALTH       141 

the  system  is  sufficient  to  affect  the  function  of  some  organ 
or  even  to  induce  a  diseased  condition.  The  actual  amount 
of  lead  consumed  by  any  individual  in  the  districts  above 
referred  to  cannot  be  estimated,  since  the  quantity  present 
in  the  water  may  have  varied  almost  with  every  time  of 
using.  It  is  possible  that  there  are  individuals  so  sus- 
ceptible that  the  most  minute  quantities  will  in  time 
produce  an  appreciable  effect.  The  only  safe  course  is  to 
prevent  waters  with  a  plumbo-solvent  action  coming  in 
contact  with  the  metal,  by  the  use  of  tin,  iron,  or  copper 
for  the  pipes  and  of  slate  for  the  cisterns.  The  so-called 
tin-lined  lead  pipe  is  not  to  be  commended,  since,  during 
the  process  of  lining,  the  tin  dissolves  a  small  amount  of 
lead,  forming  an  alloy  which  appears  to  be  almost  as  easily 
acted  upon  by  water  as  lead  itself.  Some  time  ago  I  found 
a  large  trace  of  lead  in  a  water  which  was  supposed  never 
to  have  been  in  contact  with  that  metal.  It  was  stored  in 
tinned  copper  and  passed  through  block  tin  pipes.  The 
lead  was  traced  to  the  tin  lining  of  the  copper  vessel,  and 
the  makers  denied  the  possibility  of  there  being  any  lead 
therein,  and  asked  me  to  visit  their  works  and  see  the 
process  of  "  tinning."  I  availed  myself  of  the  opportunity, 
and  found  the  tin  melted  ready  for  the  work  to  Be 
commenced.  I  was  informed  that  this  was  "  pure  "  tin, 
but  upon  further  interrogating  the  workmen  I  ascertained 
that  it  was  technically  called  "  pure "  tin  for  tinning 
purposes,  and  contained,  if  I  remember  aright,  about  15  per 
cent,  of  lead,  the  latter  being  added  to  cause  the  tin  to 
adhere  to  the  copper.  My  correspondent,  one  of  the 
partners  in  the  firm,  was  himself  ignorant  of  this  fact. 
Tin-lined  iron  pipe,  known  in  commerce  as  the  "  Health  " 
pipe,  is  absolutely  safe,  and  the  best  form  of  service  pipe  for 
all  drinking  waters.  An  interesting  sample  of  water  was 
recently  submitted  to  me  for  examination.  It  was  found 
that  the  leaden  pipes  from  the  hot-water  cistern  regularly 
split  at  the  bends  after  being  in  use  for  about  a  couple  of 


i42  WATER  SUPPLIES 

years.  The  pipes  from  the  cold  water  cistern  were  un- 
affected. The  water  proved  to  contain  only  about  1  grain 
of  carbonate  of  lime  per  gallon,  though  it  had  several 
degrees  of  hardness.  When  cold  it  had  not  the  slightest 
action  upon  lead,  but  after  being  boiled  it  attacked  the 
metal  so  energetically  that  I  have  no  doubt  of  its  being 
able  to  erode  the  pipes  in  the  manner  described.  Doubtless, 
at  the  angles  slight  fissures  would  be  found  in  the  lead,  and 
by  the  prolonged  action  of  the  water  these  would  ultimately 
extend  right  through  the  thickness  of  the  pipe. 

The  various  ways  in  which  lead  can  be  removed  from 
water,  and  by  which  an  "  active  "  water  can  be  rendered 
"  inactive  "  will  be  described  in  a  later  chapter. 

Diseases   due   to   Specific   Organisms. 

Whilst  waters  containing  impurities  both  of  vegetable 
and  animal  origin  are  constantly  being  drunk  with  apparent 
impunity,  yet  in  almost  all  cases  it  is  found  that  sooner  or 
later  outbreaks  of  disease  occur,  pointing  to  some  specific 
polluting  material  having  gained  access  to  them.  The 
danger  naturally  is  greatest  where  the  filth  which  contami- 
nates the  water  is  derived  from  human  excrement,  whether 
it  be  discharged  from  sewers  into  our  rivers,  or  oozes 
through  a  defective  cesspit,  cesspool,  or  drain  into  wells  or 
tanks,  or  whether  it  percolates  through  the  sewage-sodden 
ground  around  our  habitations,  and  in  an  imperfectly 
filtered  and  purified  condition  reaches  the  subsoil  water 
from  which  our  supplies  are  derived.  In  such  cases  our 
observations  only  require  to  be  continued  sufficiently  long 
to  ensure  an  outbreak  of  some  specific  disease  being 
recorded.  Of  this  many  illustrations  will  be  given  when 
typhoid  fever  and  cholera  are  being  considered.  There  are 
other  diseases,  however,  which  are  due  to  specific  organisms 
which  apparently  may  occur  in  water  free  from  pollution  by 
sewage.  Of  these  the  most  important  is  malaria,  or 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       143 

malarial  fever,   a  disease  which  in  many  countries  is  far 
more  prevalent  than  any  other. 

Malaria. — Malarial  disease  is  at  the  present  time  almost 
unknown  in  England.  Even  in  the  districts  in  which  ague 
was  most  prevalent,  as  in  the  fens  of  Lincolnshire  and 
marshes  of  Essex,  it  is  now  but  rarely  met  with.  Whether 
this  be  due  to  better  drainage  or  purer  water  supplies  it  is 
impossible  to  decide,  probably  both  are  important  factors. 

The  organism  causing  this  disease  is  usually  introduced 
into  the  system  by  the  bite  of  a  certain  species  of  mosquito ; 
but  its  life  history  is  not  sufficiently  well  known  to  enable 
us  to  prove  or  disprove  possible  infection  by  means  of  drink- 
ing water.  Swampy  districts  are  most  frequently  malarious, 
but  they  are  not  necessarily  so,  and  swamp  water  which  is 
usually  loaded  with  vegetable  matter  is  frequently  drunk 
without  causing  malaria.  This  is  doubtless  due  to  the  fact 
that  whilst  the  natural  habitat  of  the  malarial  parasite 
discovered  by  Laveran  is  in  tropical  water-logged  districts, 
yet  it  is  not  of  universal  occurrence  in  such  districts,  and 
may,  under  certain  conditions,  of  which  we  are  yet  ignorant, 
thrive  elsewhere.  The  disease,  however,  is  only  of  interest 
here,  inasmuch  as  there  is  evidence  sufficient  to  warrant  us 
in  believing  that  one  of  the  modes  in  which  the  malarial 
organism  enters  the  system  is  with  the  drinking  water. 
Thus  Dr.  Parkes,  during  the  Crimean  War,  questioned  the 
inhabitants  of  the  highly-malarious  plains  of  Troy,  and 
found  that  it  was  universally  believed  "  that  those  who 
drank  marsh  water  had  fever  at  all  times  of  the  year,  while 
those  who  drank  pure  water  only  got  ague  during  the  late 
summer  and  autumnal  months."  Mr.  Bettington,  of  the 
Madras  Civil  Service,  who  carefully  investigated  this 
subject,  obtained  very  strong  evidence  of  the  production  of 
malaria  by  drinking  water.  In  one  village  he  found  that 
fever  was  prevalent  amongst  those  who  drank  water  from 
one  source — a  tank  fed  partly  by  marsh  water — but  absent 
amongst  those  who  obtained  water  from,  other  sources.  In 


I44 


WATER  SUPPLIES 


another  village  in  which  fever  was  endemic,  it  entirely 
disappeared  when  a  better  water  supply  was  obtained.  In 
the  Wynaad  district,  where  malaria  is  very  fatal,  he  says 
that  it  "  is  notorious  that  the  water  produces  fever  and 
affections  of  the  spleen."  Boudin  relates  that  "  on  board 
a  French  ship-of-war  bound  from  Bona  to  Marseilles,  a 
malignant  epidemic  of  malarial  fever  broke  out  at  sea,  13 
men  dying  out  of  a  crew  of  229,  whilst  98  were  more 
or  less  seriously  ill,  and  had  to  be  sent  into  hospital  at 
Marseilles;  it  came  out,  on  inquiry,  that  the  vessel  had 
shipped  at  Bona  several  casks  of  marshy  water,  which  had 
given  rise  to  lively  dissatisfaction  among  the  crew  on 
account  of  its  disagreeable  smell  and  taste,  and  that  not 
a  single  case  of  sickness  had  occurred  among  those  of  the 
crew  who  had  drunk  pure  water."  Notwithstanding  such 
apparently  conclusive  evidence,  many  observers  doubt  the 
production  of  malaria  by  drinking  water.  Amongst  the 
more  recent  ones  may  be  cited  Mr.  North,  who  spent  much 
time  in  investigating  the  cause  of  this  disease  in  and 
around  Rome.  He  observes  that  the  healthiest  parts  of  the 
city  of  Rome  are  supplied  with  water  from  springs  which 
arise  in  a  locality  so  unhealthy  that  there  is  great  risk  to 
health,  and  even  to  life,  in  passing  the  nights  there  during 
certain  seasons  of  the  year.  He  concludes  that  there  is  not 
sufficient  proof  of  the  disease  being  conveyed  by  water, 
notwithstanding  that  such  a  belief  is  universal  in  all 
districts  in  which  the  disease  prevails. 

Surgeon-Mapr  R.  R.  H.  Moore,  in  a  recent  article  on 
"  Water  Supplies  and  Malarial  Fever  "  (Journal  of  State 
Medicine,  vol.  vi.,  p.  116),  criticises  the  evidence  with 
reference  to  the  outbreak  on  the  ship  "  Argo,"  and  quotes 
another  account,  which  says  that  "  during  the  passage  of 
eighteen  days  salt  provision  had  to  be  used  owing  to  the 
scarcity  of  fresh  water,  and  which,  from  being  stored  in 
old  casks,  quickly  became  bad.  Under  these  insanitary 
conditions,  disease  of  a  serious  nature  set  in3  symptoms  of 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       145 

typhoid  fever  appeared,  and  about  30  of  the  soldiers  died 
either  on  board  ship  or  in  lazaret  at  Marseilles."  He 
contends  that  the  great  objection  to  most  of  the  instances 
in  which  water  is  alleged  to  have  caused  malarial  fever 
is  that  they  have  occurred  in  places  where  the  disease  is 
endemic,  and  where  it  is  almost  impossible  to  demonstrate 
positively  that  the  poison  did  not  enter  the  system  through 
the  medium  of  air.  He  is  unable  to  understand  how 
it  is  that  the  idea  still  holds  its  ground,  considering  how 
little  there  is  to  be  said  in  support  of  it,  unless  it  is  due 
to  the  great  influence  of  Parkes ;  for  it  is  evident  from  his 
work  that  the  water  theory  was  a  favourite  one  with  him. 
Many  continental  epidemiologists  have  given  up  this  theory, 
but  the  most  recent  observers  (Laveran,  Babes,  and  Van- 
dyke Carter)  believe  that  the  infection  may  be  caused  by 
the  drinking  water. 

Enteric  or  Typhoid  Fever. — The  production  of  typhoid 
fever  by  the  use  of  polluted  drinking  water  is  an  indis- 
putable fact,  and  the  instances  which  can  be  adduced  in 
proof  of  this  statement  are  so  numerous  that  it  is  difficult 
to  make  a  selection.  The  following  examples  are  given  not 
only  as  illustrating  such  proof,  but  also  on  account  of  their 
being  typical  of  outbreaks  produced  by  the  pollution  of  the 
water  in  most  diverse  manners.  In  some  the  source  of  the 
infected  material  was  almost  self-evident,  in  others  the 
discovery  of  the  mode  by  which  the  water  became  contami- 
nated taxed  the  ingenuity  and  patience  of  the  investigator 
to  the  utmost,  whilst  in  others  specific  pollution  could  only 
be  inferred. 

At  Lausen  in  Switzerland  an  outbreak  of  typhoid  fever 
occurred  *  amongst  that  portion  of  the  population  which 
derived  its  drinking  water  from  a  certain  spring.  On  the 
other  side  of  the  hill  was  a  brook  which  passed  under- 
ground, and  it  was  suspected  that  this  stream  really  fed  the 

*  In  August,  1872.    Deutscli.  Arch.  f.  klin.  Med.  Bd.  xi.,  1873,  S.  237. 

IO 


146  WATER  SUPPLIES 

spring  in  question.  When  flour  was  added  to  the  brook 
water,  however,  none  of  it  made  its  appearance  in  the 
spring,  but  when  salt  was  dissolved  in  the  stream,  its  pres- 
ence was  soon  after  discovered  at  Lausen.  Obviously  the 
water  in  traversing  the  hill  became  filtered  so  completely 
as  to  remove  all  the  particles  of  the  flour,  yet  such  filtration 
had  failed  to  remove  the  typhoid  poison,  which  it  was 
proved  had  been  introduced  into  the  brook  by  the  stools  of 
a  patient  suffering  from  that  disease.  Shortly  after  the 
fouling  of  the  stream  typhoid  fever  broke'  out  amongst  those 
who  used  the  spring  water,  67  persons  being  attacked 
within  10  days. 

In  1872  an  epidemic  occurred  at  Nunney  (Somerset- 
shire) which  Dr.  Ballard  investigated  on  behalf  of  the  Local 
Government  Board.  He  found  that  the  brook  supplying 
the  village  with  water  had  been  specifically  polluted  by  the 
drainage  of  a  house  into  which  typhoid  fever  had  been 
introduced  from  without.  76  cases  occurred  amongst  a 
population  of  832. 

In  1874  a  serious  outbreak  at  Over  Darwen  (Lancashire), 
was  investigated  for  the  Local  Government  Board  by  Dr. 
Stevens.  It  was  proved  that  a  patient  who  had  contracted 
the  disease  elsewhere  resided  in  a  house  the  drain  from 
which  was  blocked  and  defective  at  a  point  where  it 
crossed  a  leaking  water  main.  Dr.  Stevens  succeeded  in 
demonstrating  that  the  sewage  was  sucked  into  the  water 
main  freely  and  regularly.  The  disease  spread  rapidly, 
and  no  less  than  2,035  persons,  or  nearly  one-tenth  of  the 
whole  population,  were  attacked  within  a  very  short  period. 

In  1882  a  serious  outbreak  occurred  at  Banger 
(N.  Wales),  which  ultimately  affected  540  persons  out  of  a 
population  of  about  10,000.  In  May  a  case  of  enteric  fever 
had  occurred  in  an  isolated  house  that  discharged  its 
sewage  into  a  small  stream  which  at  a  point  lower  down 
joined  a  larger  stream,  the  Afon  Gaseg,  from  which  Bangor 
derived  its  water  supply.  During  June  two  other  cases 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       147 

occurred  in  the  above  house,  and  specifically  polluted  sewage 
continued  to  find  its  way  into  the  Afon.  The  filter  beds 
were  said  to  be  very  imperfect,  and  these  were  disturbed  on 
30th  June  by  the  bursting  of  a  water  main.  Within  a 
fortnight  of  this  accident  the  outbreak  commenced,  attack- 
ing simultaneously  various  localities  in  the  town. 

In  1879  an  epidemic  occurred  at  Caterham  and  Redhill 
in  Surrey.  Within  a  fortnight  179  persons  were  attacked. 
Of  the  143  houses  first  infected,  136  had  their  water  supply 
exclusively  from  the  public  mains,  and  in  the  other  7 
houses  this  water  was  occasionally  used.  Of  the  2,258 
houses  in  the  two  parishes,  1,343  derived  water  from  the 
mains;  the  remainder  were  chiefly  supplied  from  wells. 
Dr.  Thome,  who  investigated  the  outbreak,  found  that  just 
prior  to  the  outbreak,  the  Water  Company  had  been 
enlarging  their  reservoirs  and  had  sunk  a  shaft  down  to 
the  conduit.  One  of  the  labourers  employed  in  this  conduit 
had  contracted  typhoid  fever  at  Croydon,  but  was  able  to 
continue  his  work.  Diarrhoea  was  profuse,  and  as  he  could 
not  "conveniently  leave  the  shaft  his  motions  were  passed 
at  the  bottom  and  were  afterwards  washed  into  the  conduit. 
"  The  outbreak  took  place  simultaneously  in  Caterham  and 
Redhill  exactly  fourteen  days  after  the  water  supply  had 
been  befouled  in  this  manner." 

In  1880  a  case  of  typhoid  fever  was  introduced  into  the 
town  of  Nabburg  (pop.  1,900)  and  spread  among  the 
inmates  of  the  infected  house ;  about  a  fortnight  later 
other  cases  occurred  amongst  the  inhabitants  of  the  row 
in  which  this  house  was  situated,  and  within  the  next 
fortnight  about  half  (35  out  of  77)  the  inhabitants  were 
suffering  from  typhoid  fever.  Three  out  of  the  row  of  17 
houses  and  the  poor's-house  remained  free  from  the  disease, 
and  it  was  found  that  these  were  supplied  with  water  from  a 
well,  whilst  all  the  others  derived  their  water  supply  from  a 
tank  fed  by  a  pipe  which  ran  through  a  slop  puddle.  This 
slop  puddle  received  the  drainage  from  a  dung-heap  upon 


148  WATER  SUPPLIES 

which  typhoid  excreta  had  been  thrown,  and  the  water 
pipe  was  perforated  at  the  part  where  it  was  covered  by  the 
filth.  As  soon  as  these  pipes  were  repaired  the  epidemic 
ceased. 

The  danger  which  may  arise  from  the  proximity  of  a 
sewage  farm  to  a  water  supply  is  well  exemplified  by  the 
Report  of  Dr.  Page  to  the  Local  Government  Board  on  an 
outbreak  of  typhoid  fever  at  Beverley  (Yorkshire)  in  1884. 
The  sewage  of  the  East  Riding  County  Lunatic  Asylum 
was  disposed  of  upon  a  field  next  the  Water  Company's 
well  and  works,  and  the  effluent  water  "  following  in  the 
direction  of  the  natural  line  of  drainage  "  percolated 
towards  the  Company's  premises.  Certain  defects  were 
found  in  the  well,  and  prior  to  the  outbreak  cases  of 
typhoid  fever  had  occurred  in  the  Asylum.  The  total 
number  of  households  invaded  was  125,  and  there  were  231 
cases,  12  of  which  proved  fatal. 

In  all  the  above  instances  the  source  of  the  specific 
pollution  was  Discovered.  In  the  following  there  was 
proof  only  of  the  contamination  of  the  water  by  sewage. 
This  must  have  contained  the  specific  organism  of  typhoid 
fever,  but  the  cases  which  introduced  these  into  the  sewage 
remain  undiscovered,  though  in  some  instances  the  possi- 
bility of  such  specific  contamination  was  proved. 

In  1867  an  outbreak  of  typhoid  fever  occurred  at 
Sherborne  in  Dorset.  Dr.  Blaxall,  who  was  instructed  by 
the  Local  Government  Board  to  investigate  it,  attributed 
it  to  the  direct  connection  of  the  water  supply  pipes  with 
the  closet  pans.  Some  of  the  taps  to  these  pipes  were 
broken.  When  the  water  was  turned  off  at  the  mains,  the 
foul  air  from  the  closet  pans,  or,  if  the  pan  happened  to  be 
full  of  excrement,  actual  faecal  matter  could  be  drawn  into 
the  water  pipes. 

In  1873  Dr.  Buchanan  contributed  a  most  important 
report  to  the  Local  Government  Board  on  an  outbreak  of 
.typhoid  fever  at  Caius  College,  Cambridge.  Twelve  of  the 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       149 

fifteen  cases  which  occurred  were  in  Tree  Court,  and  Dr. 
Buchanan  could  find  no  condition  capable  of  explaining  the 
outbreak  but  the  pollution  of  the  water  in  the  branch 
main  which  supplied  this  court  alone.  He  found  that  the 
closets  in  this  court  were  the  only  ones  in  the  College 
flushed  directly  from  the  main,  and  that  on  account  of 
defects  in  the  valve  taps,  when  there  was  an  intermission 
in  the  water  supply  a  reflux  of  air  and  water  took  place 
into  the  main.  There  had  been  two  intermissions  during 
the  term,  one  a  fortnight  before  the  first  case,  and  the 
other  a  fortnight  before  a  more  general  outbreak.  Inside 
the  pipes  a  dirty-looking  layer  was  found,  which  upon 
analysis  proved  to  be  derived  from  sewage ;  hence  doubtless 
not  only  sewer  gas  but  also  actual  liquid  filth  had  been 
sucked  from  the  closet  pans  into  the  pipes. 

In  1887  an  interesting  outbreak  occurred  in  the  Mountain 
Ash  Urban  Sanitary  District  (Glamorganshire),  which 
comprises  several  mining  villages.  The  cases  ultimately 
numbered  over  500,  and  the  localisation  was  such  as  to 
throw  suspicion  upon  one  particular  branch  of  the  public 
water  mains.  The  only  possible  explanation  appeared  to 
be  the  fouling  of  the  water  in  this  branch  at  a  particular 
point.  The  ground  was  accordingly  opened  there,  and  it 
was  found  that  the  water  main  passed  through  some  drains 
which  had  been  "  wantonly  smashed  "  for  this  purpose,  and 
the  main  itself  was  defective  and  leaking.  Prior  to  the 
outbreak  there  had  been  intermissions  in  the  supply, 
allowing  the  fluid  filth  by  which  the  pipe  was  surrounded 
to  be  sucked  into  it,  and  so  contaminate  the  water  passing 
through  that  particular  branch. 

The  following  outbreak,  due  to  polluted  ground  water,  is 
typical  of  a  large  number  which  have  been  reported  from 
time  to  time  in  districts  deriving  their  water  supplies  from 
wells  sunk  in  a  polluted  subsoil.  At  Terling,  in  Essex,  an 
epidemic  of  typhoid  fever  occurred  in  1867.  Out  of  a 
population  of  about  900,  no  less  than  260  were  attacked 


150  WATER  SUPPLIES 

within  two  months.  The  wells  supplying  the  cottages  were 
in  close  proximity  to  the  privies,  cesspits,  bumbies,  and 
manure  heaps.  Towards  the  end  of  a  period  of  drought  a  case 
of  typhoid  fever  occurred  which  probably  was  imported. 
Three  weeks  later,  and  after  a  heavy  rainfall,  the  disease 
broke  out  with  alarming  violence.  The  well  waters  were 
proved  at  all  times  to  be  seriously  contaminated,  but  until 
the  introduction  of  the  specific  pollution  the  village  had 
been  free  from  the  disease.  In  the  filth-sodden  soil  the 
typhoid  bacillus  had  probably  found  a  suitable  nidus  for 
its  rapid  multiplication ;  thus  the  heavy  rainfall  would  not 
only  wash  impurities  into  the  wells  from  the  surface,  but 
wash  the  organisms  out  of  the  soil  into  the  rising  ground 
water  which  supplied  the  wells. 

The  very  serious  outbreak  of  typhoid  fever  which 
recently  occurred  (1897)  at  Maidstone  is  worthy  of  more 
detailed  attention.  Here  the  implicated  water,  though 
said  to  be  derived  from  a  spring,  was  really  collected 
beneath  the  ground  surface,  and  was  nothing  more  than  a 
very  shallow  well  supplied  with  water  directly  from  the 
subsoil,  and  indirectly  through  a  series  of  adits,  in  this 
case  consisting  of  drain  pipes  laid  only  2  to  3  feet  below 
the  ground  surface.  The  only  houses  near  were  a  farm 
house  upon  higher  ground,  and  a  row  of  cottages  on  lower 
ground.  Very  much  nearer,  however,  was  an  erection  used 
for  the  temporary  accommodation  of  hop-pickers,  and,  so  far 
as  I  could  see,  without  any  sanitary  conveniences  whatever. 
From  my  examination  of  the  locality,  I  should  certainly 
say  that  both  the  farm  and  the  cottages  were  without  the 
sphere  of  influence,  and  could  not  possibly  have  con- 
taminated the  water.  The  top  of  the  well,  however,  was 
not  raised  above  the  ground  surface,  but  in  a  little  hollow, 
and  only  covered  by  a  wooden  framework  and  lid.  The 
hop-pickers,  or  anyone  else  for  that  matter,  could  micturate 
or  defsecate  in  the  hollow  without  let  or  hindrance,  but  it 
is  not  necessary  to  suppose  that  such  direct  pollution  took 


IMPURE   WATER,  ITS  EFFECT   UPON  HEALTH       151 

place.  The  subsoil  water  level  was  at  this  point  close  to 
the  ground  surface,  and  at  the  highest  point  above  in  the 
hop  gardens  the  subsoil  water  cannot  have  been  more  than 
2  or  3  feet  from  the  surface,  or  the  pipe  drains  would  not 
have  been  laid  at  that  depth.  These  drains  ran  under  the 
hop  garden,  and  it  is  the  subject  of  common  know- 
ledge that  such  gardens  are  very  highly  manured.  Assum- 
ing that  this  two  or  three  feet  of  soil  always  retained 
its  maximum  purifying  and  filtering  powers,  no  one 
would  dare  to  assert  that  it  was  sufficient  to  prevent 
any  specific  polluting  matter  laid  on  the  surface  from 
entering  the  drains  and  passing  into  the  well.  But 
in  dry  seasons  the  soil  becomes  parched  and  cracked,  and  in 
this  condition  filth  could  probably  be  washed  directly  into 
the  drains;  in  any  case  the  filtering  would  be  seriously 
reduced  in  efficiency.  The  study  of  this  case  therefore 
teaches  no  new  lessons,  and  there  is  no  cause  for  surprise 
that  water  from  such  a  source  should  sooner  or  later  become 
specifically  infected,  and  produce  an  epidemic  of  typhoid 
fever.  The  case  has  been  more  particularly  referred  to 
because  it  has  caused  a  great  deal  of  needless  alarm,  and 
an  unreasoning  prejudice  against  the  use  of  subsoil  water 
for 'public  water  supplies. 

In  1889  an  outbreak  occurred  at  New  Herrington, 
Durham,  278  cases  being  reported  between  the  1st  April 
and  7th  June  out  of  a  population  of  3,600.  Dr.  Page 
discovered  that  a  deep  well  supplying  the  village  was  being 
contaminated  by  the  sewage  of  a  farm  three-quarters  of  a 
mile  away.  This  sewage  discharged  into  a  tank,  and  the 
overflow  disappeared  down  a  fissure  in  the  ground  and 
ultimately  found  its  way  into  the  well  at  a  point  45  feet 
below  the  surface.  Two  tons  of  salt  were  put  down  this 
fissure  and  soon  after  the  amount  of  chlorine  in  the  well 
water  began  to  rise,  ultimately  increasing  from  4  grains  to 
24  grains  per  gallon.  Specific  pollution,  however,  was  not 
demonstrated,  as  no  case  of  typhoid  fever  was  known  to 
have  occurred  at  the  farm  for  years. 


152  WATER  SUPPLIES 

Dr.  Maclean  Wilson  recently  investigated  for  the  Local 
Government  Board  an  outbreak  of  enteric  fever  at  Chester- 
le-Street,  between  Durham  and  Newcastle.  Of  the  1,100 
houses  in  the  village  some  40  per  cent,  were  supplied  by  the 
Consett  Water  Company,  and  some  60  per  cent,  by  the 
Chester-le-Street  Company.  Of  the  41  infected  households, 
all  but  2  derived  water  from  the  latter  source,  and  these  2 
were  amongst  the  initial  cases,  "  possibly  not  due  to  the 
cause  producing  the  general  outbreak."  The  Chester-le- 
Street  Company  draws  its  supply  from  the  Stanley 
Burn,  about  two  miles  above  the  village.  Above  the 
intake  quite  a  large  population  drains  directly  or  in- 
directly into  the  stream.  In  a  group  of  cottages  at 
Southmoor  a  series  of  cases  of  typhoid  fever  had 
occurred  in  October,  1892,  and  January  and  February, 
1893,  and  the  bowel  discharges  of  these  patients  passed 
into  a  stream  which  forms  a  tributary  of  the  Stanley 
Burn.  The  nitration  of  this  water  before  being  sup- 
plied to  the  consumers  does  not  appear  to  have  been 
satisfactory.  The  outbreak  may  be  said  to  have  commenced 
on  14th  November,  1892,  and  came  to  an  end  in  mid-March. 
Dr.  Wilson  concluded  that  "  there  appeared  nothing  in  the 
inter-relations  of  the  sufferers  by  fever,  nothing  in  the  milk 
supplies  used  by  them,  and  nothing  in  their  sanitary 
surroundings  in  the  least  likely  to  afford  a  common  source 
of  infection.  On  the  other  hand  is  the  fact  that  so  many 
persons  using  the  same  polluted  water  suffered,  while  their 
neighbours  who  used  other  water  escaped.  Furthermore, 
there  occurred  shortly  before  each  of  two  outbreaks  of 
the  fever,  opportunity  for  the  bowel  discharges  of  enteric- 
fever  patients  gaining  access  to  the  particular  stream 
which  afforded  the  water  supply  of  invaded  households  in 
Chester-le-Street." 

The  dissemination  of  typhoid  fever  by  river  waters  is  a 
subject  of  the  greatest  importance,  and  has  already  been 
referred  to  when  rivers  were  being  considered  as  a  source 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       153 

of  water  supply.     As  few  rivers  of  any  magnitude  escape 
pollution  by  sewage,  the  great  question  is,   whether  such 
waters  can  safely  be  used  for  supplying  towns  with  drinking 
water.     That  exceedingly  polluted  river  water  may  be  used 
for  long  periods  without  producing  an  outbreak  of  typhoid 
fever  is  undoubted,  but  can  complete  immunity  be  ensured  ? 
If  the  water  used  be  drawn  many  miles  below  the  lowest 
point  of  contamination,   if  it  be   thoroughly  filtered,   and 
every    possible    precaution    be    taken    to    avoid    collecting 
water  when  the  river  has  been  disturbed  by  heavy  rains 
and   floods,    is   all   danger   removed?     The   answer   to   this 
would  depend  upon  the  amount  of  reliance  to  be  placed 
upon  the   safeguards   which   depend   upon   human   agency. 
Can  all  accidents  be  guarded  against?     Can  perfect  filtra- 
tion be  secured  at  all  seasons  and  under  all  circumstances? 
To  the  temporary  break-down  of  a  filter  bed,  Koch  attri- 
butes  the   recent   outbreak   of   cholera  at  Hamburg   (vide 
cholera).     A  similar  accident  might  lead   to  an   epidemic 
of    typhoid    fever,    assuming    that    the    river    water    were 
specifically    polluted    at    the    time.      This    coincidence    of 
specific  pollution  and  defective  action  of  the  filters  may  be 
an  extremely  improbable  one,  but  the  degree  of  probability 
depends  upon  many  as  yet  imperfectly  known  factors,  such 
as  the  length  of  time  which  the  typhoid  bacillus  can  live  in 
river  water,  or  in  the  sedimentary  matter  on  its  bed,  the 
conditions  under  which  mere  filtration  can  be  depended  on 
to  remove  the  organism,  etc. 

In  1891  Mr.  Hiram  F.  Mills,  a  member  of  the  Board  of 
Health  of  Massachusetts,  prepared  for  that  board  a  report 
on  "  Typhoid  Fever  in  its  Relation  to  Water  Supplies." 
He  found  that  in  Massachusetts  the  highest  typhoid  death- 
rates  were  not  in  the  cities  but  in  the  towns  supplied  with 
well  water.  The  introduction  of  purer  water  supplies  had 
in  all  cases  been  followed  by  a  decrease  in  the  typhoid 
mortality,  but  in  two  cities,  Lowell  and  Lawrence,  with  a 
population  of  123,000,  there  had  been  during  the  previous 


154  WATER  SUPPLIES 

twelve  months  about  one-third  more  deaths  than  in  the 
city  of  Boston  with  four  times  the  population.  The  cause 
of  this  excessive  prevalence  of  typhoid  fever  was  investi- 
gated, and  it  was  found  that  prior  to  the  outbreaks  the 
Lowell  water  supply  had  been  contaminated  by  the  faeces 
of  typhoid  patients  discharged  into  Stony  Brook,  only  three 
miles  above  the  intake  of  the  water-works.  This  pollution 
was  followed  in  about  three  weeks  by  a  very  rapid  increase 
in  the  number  of  deaths  from  typhoid  fever  in  Lowell,  and 
about  six  weeks  later  by  an  alarming  increase  in  the 
number  of  deaths  in  Lawrence,  whose  water  supply  is 
drawn  from  the  Merrimac  River,  nine  miles  from  where 
the  Lowell  sewage  enters  the  river.  An  examination  of  the 
water  from  the  service  pipes  of  the  city  of  Lawrence  led  to 
the  discovery  of  the  typhoid  bacillus  therein.  These  two 
cities  are  the  only  cities  in  the  State  which  draw  their 
water  for  drinking  from  a  river  into  which,  within  twenty 
miles  above,  sewage  is  publicly  discharged.  "  The  amount 
of  sewage  that  has  directly  entered  tne  river  (Merrimac) 
and  its  branches  during  the  chemical  examination  of  the 
past  three  years  is  estimated  to  be  about  1  gallon  in  600 
gallons  of  the  river  water  passing  Lawrence,  and  there  has 
been  no  more  impurity  in  the  water,  that  could  be  detected 
by  chemical  analysis,  than  in  about  one-half  of  the  drinking 
water  supplies  of  the  State  obtained  from  ponds  and 
streams :  but  the  facts  which  have  been  presented,  showing 
that  these  two  cities  have  so  much  higher  death-rate  from 
typhoid  fever  than  any  other  cities  of  the  State,  together 
with  what  is  known  of  the  relation  of  typhoid  fever  to 
sewage-polluted  drinking  water,  are  the  strongest  grounds 
for  concluding  that,  even  with  the  small  amount  of  organic 
impurity  in  the  water  as  shown  by  chemical  analysis,  the 
germs  of  this  disease  are  able  to  pass,  and  do  pass,  from  one 
city  to  the  other  in  the  water  of  this  river."  Experiments 
were  made  to  ascertain  whether  the  typhoid  bacillus  could 
withstand  a  temperature  only  a  little  above  freezing-point 


IMPURE  WATER,  ITS  EFFECT   UPON  HEALTH       155 

long  enough  to  pass  from  the  Lowell  sewers  to  the  water 
mains  of  Lawrence.  It  was  calculated  that  the  Lowell 
sewage  would  reach  the  intake  of  the  Lawrence  Waterworks 
in  eight  hours,  and  would  pass  through  the  reservoirs  into 
the  mains  within  ten  days.  Typhoid  germs  kept  in  ice-cold 
water  were  found  to  be  killed  somewhat  rapidly,  but  it 
was  not  until  the  twenty-fifth  day  that  all  the  bacilli  had 
perished.  Evidently,  therefore,  the  typhoid-fever  germs 
from  the  Lowell  sewers  may  live  in  winter  to  enter  the 
Lawrence  mains  in  great  numbers.  The  fact  that  more 
cases  of  fever  occurred  near  the  reservoirs  than  in  the 
districts  towards  the  ends  of  the  mains  is  explained  by  the 
bacteriological  examination  of  the  water,  which  proved 
that  the  number  of  bacteria  in  the  water  gradually 
diminishes  with  the  distance  from  the  reservoirs.  The 
Merrimac  is  a  large,  swift  river,  and  Dr.  Edwards  denied 
that  the  ejecta  of  a  few  persons  could  possibly  contain  a 
sufficient  number  of  germs  to  lay  low  some  hundreds  of 
people  in  Lowell.  He  elaborately  computed  the  dilution 
which  the  ejecta  had  undergone,  and  came  to  the  conclusion 
that  the  water  theory  involved  a  physical  impossibility, 
and  consequent  reductio  ad  absurdum.  A  somewhat  similar 
conclusion  was  arrived  at  by  the  Metropolitan  Water 
Supply  Commission  after  considering  the  evidence  adduced 
for,  and  against,  the  theory  of  the  Tees  River  water  being 
the  cause  of  the  typhoid  epidemic  in  the  towns  in  that 
river  valley.  As  we  know  nothing  of  the  number  of  bacilli 
which  a  typhoid  patient  may  discharge,  nor  of  the  number 
which  are  necessary  to  produce  an  attack  of  the  disease, 
arguments  and  speculations  of  this  character  can  have  but 
little  weight. 

It  is  interesting  to  note  that  in  1892-93  another  outbreak 
of  typhoid  fever  occurred  in  the  Merrimac  valley,  involving 
Lowell,  Lawrence,  and  Newburyport.  Dr.  Sedgwick,  who 
again  conducted  the  investigation,  found  that  in  December, 
1892,  there  was  a  marked  increase  in  the  number  of  cases 


156  WATER  SUPPLIES 

of  typhoid  fever  in  Lowell.  It  was  predicted  that  Lawrence 
would  soon  suffer,  and  before  long  fever  began  to  increase 
there ;  and  at  the  same  time  a  very  unusual,  and  at  first 
apparently  unaccountable  outbreak  occurred  at  Newbury- 
port,  lying  below  these  cities  at  the  mouth  of  the  Merrimac. 
Contrary  to  the  advice  of  the  State  Board  of  Health,  it  was 
discovered  that,  owing  to  a  scarcity  of  water,  the  company 
at  Newburyport  had  for  some  time  been  drawing  water 
from  the  river.  "  The  occurrence  of  this  epidemic  in 
Newburyport,"  says  Dr.  Sedgwick,  "  and  its  apparent  con- 
nection with  the  outbreaks  in  Lowell  and  Lawrence,  must 
be  accounted  one  of  the  most  interesting  phenomena  in  our 
whole  series  of  investigations,  and  may  serve  to  confirm  the 
truth  of  the  saying  that  '  no  river  is  long  enough  to  purify 
itself.'  " 

In  the  same  year  (1892),  an  outbreak  of  typhoid  fever 
occurred  at  Chicopee  Falls.  Cases  of  fever  had  occurred 
above  the  intake  of  the  Water  Company  from  the  Chicopee 
River;  and  everything  pointed  to  this  infection  of  the 
public  water  supply  as  the  cause. 

Tees  Valley  Epidemic. 

The  continued  prevalence  of  typhoid  fever  in  the  Tees 
valley  and  the  occasional  occurrence  of  more  or  less  exten- 
sive epidemics,  caused  the  Local  Government  Board  to 
instruct  their  inspector,  Dr.  Barry,  to  visit  the  district  and 
fully  investigate  all  the  circumstances,  and,  if  possible, 
discover  the  cause. 

Two  epidemic  outbursts  occurred  here,  one  in  September 
and  October,  1890,  and  the  other  in  January  and  February, 
1891.  Each  outbreak  was  most  marked  during  a  six-week 
period.  Out  of  1,463  cases,  91  per  cent,  occurred  in  three 
out  of  the  ten  registration  districts  embraced  by  the  Tees 
valley.  These  three  districts  comprised  the  towns  of 
Darlington,  Stockton,  Middlesborough,  South  Stockton, 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       157 

Ormesby,  Normanby,  Eston,  and  Kirkheaton,  and  the  two 
rural  districts  of  Darlington  and  Stockton.  The  possibility 
of  these  epidemic  outbreaks  being  due  to  infected  milk 
supplies,  to  defective  systems  of  sewerage  and  drainage,  or 
of  faulty  excrement  and  refuse  disposal,  was  fully 
considered.  Many  insanitary  conditions,  of  course,  were 
found,  but  their  distribution  was  not  such  as  could  afford, 
in  Dr.  Barry's  opinion,  a  probable  cause  for  the  outburst  of 
disease.  Milk  as  a  factor  was  easily  excluded.  When  the 
water  supply  was  examined,  Dr.  Barry  found  that  nearly 
half  the  population  in  the  above  districts  obtained  their 
water  from  the  river  Tees  through  the  works  of  the 
Darlington  Corporation  and  the  Stockton  and  Middles- 
borough  Water  Board. 

During  the  first  epidemic  period  33  persons  per  10,000 
of  those  using  Tees  water  were  attacked  with  enteric  fever, 
and  only  3  amongst  persons  supplied  with  water  from 
other  sources.  In  the  second  epidemic  the  attack-rates 
were  28  and  1  respectively.  The  Tees  water  was  therefore 
gravely  incriminated,  and  its  source  was  fully  examined. 
It  was  found  that,  "  either  directly  or  indirectly,  the 
drainage  of  some  twenty  villages  and  hamlets,  as  well  as 
that  of  the  town  of  Barnard  Castle,"  is  poured  into  the 
river  above  the  intake  of  the  water  companies.  Photo- 
lithographs,  showing  rubbish  tips  on  the  banks  of  the  river, 
and  the  outlets  of  numerous  drains  and  sewers,  accompany 
the  Report.  The  river,  in  fact,  appeared  to  be  utilised  as 
a  common  sewer.  The  introduction  of  the  specific  organism 
of  typhoid  fever,  and  the  failure  of  filter  beds,  it  is 
argued,  would  necessarily  lead  to  outbreaks  of  this  disease 
amongst  the  users  of  the  polluted  water,  and  this  is  what 
Dr.  Barry  believes  did  occur  just  prior  to  both  epidemics. 
Heavy  floods,  due  to  an  abnormal  rainfall,  and  to  the 
melting  of  snow,  washed  down  accumulations  of  filth, 
and  shortly  afterwards  enteric  fever  became  excessively 
prevalent.  "  Seldom,  if  ever,"  says  Dr.  Thorne,  the 


158  WATER  SUPPLIES 

Medical  Officer  to  the  Local  Government  Board,  "  has 
a  case  of  the  fouling  of  water  intended  for  human  con- 
sumption, so  gross  or  so  persistently  maintained,  come 
within  the  cognisance  of  the  Medical  Department,  and 
seldom,  if  ever,  has  the  proof  of  the  relation  of  the  use  of 
water  so  befouled  to  wholesale  occurrence  of  typhoid  fever 
been  more  obvious  and  patent." 

Not/withstanding  this  strongly  expressed  opinion  on  the 
part  of  the  Chief  Medical  Adviser  of  the  Local  Government 
Board,  the  members  of  the  Royal  Commission  on  the 
Metropolitan  Water  Supply,  whilst  acknowledging  that 
Dr.  Barry's  Report  constituted  "  a  formidable  indictment 
against  the  water  supply,"  were  evidently  deeply  impressed 
with  the  way  in  which  Dr.  Barry's  conclusions  were 
traversed  by  Mr.  Wilson,  the  representative  of  the  Stockton 
and  Middlesborough  Water  Board.  Mr.  Wilson  asserted 
that  the  notification  of  diseases  being  compulsory  over 
practically  the  whole  area  supplied  with  Tees  water,  and 
only  over  one-third  of  the  other  districts,  renders  the  returns 
of  the  number  of  cases  of  typhoid  fever  unreliable  for  com- 
parative purposes.  He  also  pointed  out  that  many  villages 
and  hamlets  supplied  with  Tees  water  altogether  escaped, 
and  that  the  distribution  generally  coincided  with  differ- 
ences in  sewerage  arrangements,  the  most  cases  occurring 
where  the  system  of  sewerage  was  so  faulty  that  previous 
outbreaks  of  fever  had  been  attributed  to  them  by  official 
inspectors,  and  the  probability  of  further  outbreaks  asserted. 
With  reference  to  the  effects  of  the  floods  and  the  intro- 
duction of  the  specific  poison  of  typhoid  fever,  he  replied, 
the  floods  of  13th  August  could  only  have  washed  down 
the  filth  which  had  accumulated  since  the  next  preceding 
flood  on  1st  July,  and  that  in  this  interval  there  had  been 
no  traceable  case  of  enteric  fever  above  the  intake.  The 
suggestion  that  there  may  have  been  unrecognised  cases  is 
a  "  perfectly  unsupported  hypothesis."  Mr.  Wilson's 
evidence  caused  the  Commissioners  to  refrain  from  express- 


IMPURE   WATER,  ITS  EFFECT  UPON  HEALTH       159 

ing  any  opinion  as  to  the  origin  of  the  disease ;  but  the 
concluding  paragraph  of  that  portion  of  their  Report 
dealing  with  this  question  is  very  significant.  "  That  the 
pollution  on  a  given  day  of  a  river  like  the  Tees,  with  a 
flow  of  at  least  1,000  million  gallons  in  the  twenty-four 
hours,  by  what  must  at  most  have  been  a  very  small  amount 
of  active  enteric  poison,  at  a  point  seventeen  miles  above 
the  intake,  should  so  seriously  affect  the  water  that  the 
admission  of  a  certain  limited  amount  of  it  into  the 
reservoirs  should  produce,  notwithstanding  filtration,  an 
extensive  outbreak  lasting  for  some  six  weeks,  is  a  hypo- 
thesis so  startling,  and  so  entirely  unsupported  by  previous 
experience  in  other  places,  that  it  is  fair  to  demand  the 
most  conclusive  evidence  before  accepting  it  as  proven ; 
and  though  we  attach  great  importance  to  the  opinion  of 
such  an  experienced  inspector  as  Dr.  Barry,  we  cannot  say 
that  such  conclusive  evidence  has,  in  our  opinion,  been 
brought  before  us." 

Here,  at  present,  the  matter  rests,  and  is  likely  to  rest, 
unfortunately.  When  a  Royal  Commission  regards  evidence 
as  non-conclusive,  which  the  Medical  Officer  of  the  Local 
Government  Board  asserts  is  so  conclusive  that  "  seldom, 
if  ever,  has  the  proof  of  the  relation  of  the  use  of  water  so 
befouled  to  wholesale  occurrence  of  typhoid  fever  been 
more  obvious  and  patent,"  it  behoves  those  of  more  limited 
experience,  and  less  accustomed  to  balancing  conflicting 
evidence,  to  guardedly  express  their  opinions. 

It  is  now  strongly  suspected  that  polluted  waters  may 
often  be  the  cause  of  the  endemicity  of  enteric  fever  in 
certain  localities,  and  of  the  sporadic  cases  which  occur  in 
many  towns  and  districts.  This  view  is  borne  out  by 
Dr.  Bruce  Low's  Report  (L.G.B.  Report  1893-4)  on  the 
occurrence  of  enteric  fever  amongst  the  population  of  the 
Trent  valley,  in  Lincolnshire  and  part  of  Nottinghamshire. 
The  Trent  and  its  numerous  tributaries  are  shown  to  be 
excessively  polluted  by  the  sewage  of  towns  and  villages, 


160  WATER  SUPPLIES 

by  surface  water  from  highly  manured  land,  and  by  a 
somewhat  large  population  living  in  tugs,  canal  boats,  and 
barges.  The  analyses  of  various  samples  of  Trent  water 
afford  abundant  evidence  of  this  pollution ;  and  prove  also 
that  the  stream  becomes  denied  at  so  many  points  that  no 
opportunity  is  afforded  for  the  natural  causes  of  purifica- 
tion to  produce  much  effect.  Night  soil  from  several  large 
towns  is  freely  used  upon  land  bordering  on  the  stream, 
and  much  of  the  same  filth  is  conveyed  by  boats  plying 
upon  it ;  and  when  these  barges  are  unloaded  we  hear  of 
the  fluid  filth  remaining  in  the  hold  being  pumped  into  the 
river.  Notwithstanding  this,  throughout  nearly  the  whole 
of  its  course  the  river  water  is  used  for  domestic  purposes, 
and  regarded  as  "  wholesome  and  harmless/' 

In  the  Gainsborough  Rural  Sanitary  District,  the 
Infectious  Disease  Notification  Act'  had  not  been  adopted, 
and  the  number  of  cases  of  typhoid  fever  which  had 
occurred  during  recent  years  had  to  be  ascertained  by 
inquiry  from  local  practitioners,  some  of  whom  could  only 
give  information  from  memory.  Based  upon  statistics  so 
obtained,  Dr.  Low  shows  that,  during  the  previous  four  and 
a  half  years,  the  enteric  fever  attack-rate  in  the  villages 
using  well  water  only  averaged  1.92  per  annum  per  1,000 
population,  whereas  in  the  villages  using  Trent  water  the 
attack-rate  was  29.3.  From  the  number  of  villages  and 
aggregate  population,  it  is  evident  that  the  fewest  cases 
occurred  amongst  the  more  scattered  population;  but 
whether  the  drainage  and  sewerage  arrangements  were 
satisfactory  in  the  larger  villages  where  enteric  fever  was 
more  prevalent  is  not  stated.  Neither  is  the  number  of 
deaths  from  typhoid  fever  in  each  group  given  to  confirm 
the  deductions  drawn  from  the  estimated  number  of  cases. 
Apparently  the  results  of  Dr.  .Low's  investigations  were 
communicated  to  the  Parochial  Committees  of  the  villages 
most  concerned,  and  the  unanimity  with  which  each 
declared  that  Trent  water  was  not  injurious,  and  'that  its 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       161 

village  was  in  a  healthy  state,  is  somewhat  amusing. 
Where  money  has  to  be  expended,  the  arguments  which 
will  convince  a  Parochial  Committee  that  anything  is  wrong 
have  to  be  very  conclusive  and  clinching. 

In  the  town  of  Newark  about  half  the  population  was 
until  recently  supplied  from  the  Trent,  and  the  other  half 
from  polluted  shallow  wells.  During  the  last  three  and  a 
half  years  in  which  Trent  water  was  used,  78.5  per  cent,  of 
the  notified  cases  of  enteric  fever  occurred  among  that  half 
of  the  population  using  river  water.  By  the  advice  of  the 
Medical  Officer  of  Health,  a  fresh  supply  of  pure  water  was 
obtained  from  the  new  red  sandstone  at  Edingley.  The 
amount  of  typhoid  fever  suddenly  decreased  with  the  intro- 
duction of  the  new  water  supply,  as  is  shown  in  the 
following  table,  and  it  has  since  remained  very  low.  There 
is  no  other  circumstance  known  which  could  have  produced 
this  effect,  and  we  have  either  a  marvellous  coincidence  or 
a  proof  that  the  use  of  polluted  waters  may  cause  a  high 
incidence  of  typhoid  fever  without  serious  epidemic  out- 
bursts. This  is  an  exceedingly  important  subject,  well 
worthy  of  further  investigation,  and,  in  connection  there- 
with, the  history  of  the  prevalence  of  this  fever  within  the 
metropolitan  area  is  instructive. 

In  London  many  cases  of  typhoid  fever  occur  annually 
the  source  of  which  cannot  be  traced,  and  in  the  report 
by  Dr.  Shirley  Murphy,  Medical  Officer  of  Health,  for  the 
year  1894,  the  distribution  of  these  cases  and  their  relation 
to  periods  of  flood,  etc.,  is  discussed.  He  says :  "  The 
distribution  of  cases  of  enteric  fever  throughout  the  year 
was  characterised  by  an  increase  of  prevalence  in  the  49th, 
50th,  and  51st  weeks.  Previous  experience  of  the  distribu- 
tion of  cases  of  this  disease  in  London  during  the  period 
1890-3  shows  that  this  behaviour  of  the  disease  in  1894 
was  exceptional,  and  further  inquiry  shows  that  the 
increase  was  not  due  to  any  special  local  prevalence,  but 
was  manifested  over  a  large  area  of  the  county.  .  .  .  Study 

ii 


162 


WATER  SUPPLIES 


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IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       163 

of  the  results  of  chemical  examination  of  the  waters 
supplied  by  the  London  water  companies,  and  which  are 
published  by  these  companies,  shows  an  intimate  relation 
between  the  condition  of  the  waters  as  supplied  and  the 
condition  as  to  flood  of  the  rivers  from  which  these  waters 
are  derived.  Certain  notable  floods  in  November  materially 
altered  the  condition  of  the  waters  supplied,  at  a  time 
when  there  is  reason  to  suppose  that  some  new  factor  in 
the  causation  of  enteric  fever  in  London  must  have  come 
into  operation.  Inquiry  as  to  the  behaviour  of  enteric 
fever  in  populations  in  the  vicinity  of  the  county  gives 
indication  of  some  difference  of  behaviour  of  this  disease 
in  the  population  supplied  by  water  from  the  Thames 
and  Lea,  and  in  the  population  otherwise  supplied,  the 
population  supplied  from  these  rivers  experiencing  an 
increase  of  disease  in  the  49th,  50th,  and  51st  weeks, 
corresponding  with  that  experienced  in  London. 

"  The  hypothesis  of  water-borne  contagion  appears  better 
able  than  any  other  to  afford  explanation  of  the  increase  of 
disease  in  the  weeks  in  question." 

During  recent  years  quite  a  number  of  limited  outbreaks 
of  typhoid  fever  have  been  more  or  less  definitely  traced  to 
the  use  of  milk  which  had  been  stored  in  vessels  rinsed  with 
sewage-polluted  water;  and  in  some  instances  this  water 
was  proved  to  be  specifically  infected. 

The  evidence  given  is  sufficient  to  prove  that  specifically 
polluted  water,  whether  derived  from  a  well,  spring,  or 
river,  can  provoke  an  epidemic  amongst  the  consumers  of 
such  water;  and  it  is  exceedingly  probable  that  in  those 
outbreaks  due  to  water  in  which  specific  contamination 
was  not  proved,  that  such  pollution  had  actually  taken 
place,  though  the  investigator  failed  to  discover  it.  This 
is  not  to  be  wondered  at  when  we  consider  the  exceedingly 
mild  character  of  some  typhoid  attacks.  It  is  not  at  all 
uncommon  for  labourers  suffering  from  such  slight  attacks 
to  continue  their  usual  occupations;  and  the  discharges 


164  WATER  SUPPLIES 

from  such  a  person  may  poison  a  water  supply  without  its 
ever  being  discovered,  however  experienced  the  investigator. 

Surgeon-Captain  Haynes  states  that  in  the  Bolan  Pass  in 
1877  typhoid  fevej  was  caused  by  drinking  a  few  ounces  of 
water  from  a  well  in  which  a  dead  camel  was  found,  yet 
that  the  natives  who'  had  been  drinking  the  water  some 
time  did  not  contract  the  disease.  He  also  remarks  that 
native  troops  can  live  in  barracks  which  have  had  to  be 
vacated  by  our  men  on  account  of  the  prevalence  of 
typhoid  fever  and  cholera. 

Cases  of  typhoid  fever  constantly  occur  which  appear  to 
be  due  to  sewage-contaminated  water,  and  in  which  there  is 
apparently  conclusive  evidence  that  such  sewage  has  not 
been  infected  by  typhoid  ejecta. 

To  account  for  these  cases  it  has  been  assumed  that 
the  bacillus  coli  communis,  found  in  all  faecal  matter, 
and  which  bears  some  resemblance  to  the  typhoid 
bacillus,  is  really  a  degenerate  or  attenuated  form 
of  the  latter;  and  that  under  favourable  circum- 
stances it  can  again  acquire  its  original  properties,  and 
provoke  a  typical  attack  of  typhoid  fever,  when  introduced 
into  the  system.  Whether  this  be  the  case  or  not,  the 
danger  from  drinking  sewage-polluted  water  is  sufficiently 
great  to  render  such  water  unfitted  for  a  public  supply 
unless  and  until  it  can  be  demonstrated  that,  by  filtration 
or  some  other  process,  all  disease-producing  organisms  can 
be  infallibly  removed.  This  conclusion,  derived  from  the 
consideration  only  of  the  danger  from  typhoid  fever,  is 
strengthened  greatly  by  the  fact  that  this  disease  is  only 
one  of  the  several  which  may  be  disseminated  by  drinking 
polluted  water. 

Cholera. — The  evidence  upon  which  cholera  is  classed 
amongst  the  water-borne  diseases  resembles  closely  in  its 
nature  that  which  has  been  adduced  to  prove  that  typhoid 
fever  is  disseminated  by  polluted  drinking  water.  On 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       165 

account  of  the  more  general  prevalence  of  the  latter 
disease,  the  danger  is  almost  constant ;  whilst  with  cholera 
the  danger  is  only  intermittent,  and  usually  at  long 
intervals.  The  terrible  destructiveness  of  cholera,  however, 
when  once  introduced,  makes  the  study  of  the  modes  by 
which  it  is  spread  of  the  highest  importance.  Until  the 
middle  of  the  present  century,  the  possibility  of  the  cholera 
poison  entering  the  system  with  the  drinking  water  had 
scarcely  been  suggested.  In  1849  Dr.  Snow  was  led  to 
strongly  suspect  that  the  specific  pollution  of  the  drinking 
water  was  the  cause  of  certain  localised  outbreaks  of  the 
disease  which  he  investigated  in  the  neighbourhood  of 
London.  In  1854  occurred  the  noted  outbreak  around 
Golden  Square,  Westminster,  which  was  investigated  by 
Dr.  Snow  and  others,  and  also  by  a  special  committee 
appointed  by  the  General  Board  of  Health.  During  August, 
26  cases  had  occurred  in  this  neighbourhood,  but  on  the  1st 
September  a  large  number  of  the  inhabitants  were  simul- 
taneously attacked ;  on  the  2nd  an  even  larger  number  of 
cases  occurred,  then  the  epidemic  declined  rapidly.  Over 
600  deaths  occurred  during  the  month.  Every  house  in  the 
district  was  examined,  and  every  case  as  far  as  possible 
investigated.  The  very  centre  of  the  outbreak  was  the 
western  half  of  Broad  Street,  near  the  public  pump.  An 
examination  of  the  cesspool  and  drainage  of  the  house  No. 
40,  adjoining  the  pump,  proved  conclusively  that  the 
contents  of  the  former  had  direct  access  to  the  well 
supplying  the  latter.  About  78  hours  before  the  general 
outbreak,  the  ejections  from  a  child  suffering  from  an 
attack  of  diarrhoea,  which  proved  fatal,  were  poured  into 
the  drain.  Out  of  73  persons  who  died  during  the  first 
two  days  of  the  outbreak,  61  were  in  the  habit  of  drinking 
the  pump  water.  In  a  number  of  cases  it  was  found  that 
the  drinking  of  the  water  was  followed  by  cholera;  and  a 
lady  and  her  niece,  living  quite  away  from  the  district,  who 


1 66  WATER  SUPPLIES 

had  the  water  sent  to  them,  both  died  of  the  disease  after 
drinking  it.  In  one  particular  street  of  14  houses  the  only 
4  which  escaped  without  a  death  were  those  in  which  this 
water  was  never  drunk.  In  a  factory  employing  200  people, 
where  the  water  was  used,  18  persons  died;  whereas  in  the 
adjoining  brewery,  where  the  men  never  drank  the  water, 
no  case  occurred.  Adjacent  to  these  was  a  block  of  lodging- 
houses,  supplied  with  water  from  the  pump,  and  here  there 
were  7  fatal  cases.  Certain  exceptional  cases  occurred,  of 
immunity  amongst  those  drinking  the  water,  and  of  attack 
amongst  those  not  using  it,  which  rendered  the  evidence 
not  quite  conclusive. 

The  Rivers  Pollution  Commissioners  in  their  Sixth 
Keport  describe  a  number  of  outbreaks  in  London  and 
elsewhere,  in  which  grave  suspicion  rested  upon  the  water 
supply  as  the  cause.  In  London,  during  the  1849  epidemic, 
it  was  proved  that  amongst  the  consumers  of  Thames  water 
the  mortality  increased  with  the  increased  pollution  of  the 
river  at  the  various  points  from  which  the  water  was 
abstracted.  Thus,  amongst  those  using  water  taken  from 
the  river  above  Kew,  the  mortality  was  .8  per  1,000,  whilst 
amongst  those  drinking  water  drawn  between  Battersea  and 
Waterloo  Bridge  it  was  16.3  per  1,000.  In  1854  a  similar 
coincidence  was  observed.  In  1866  the  area  chiefly  affected 
by  cholera  was  almost  exactly  that  of  the  District  supplied 
by  the  East  London  Water  Company,  which  distributed 
water  described  as  being  "  unfiltered  and  excessively 
polluted  with  sewage,"  and  which  there  were  grave  reasons 
for  suspecting  had  been  specifically  contaminated  with  the 
excrement  of  two  patients  who  had  died  of  cholera.  They 
also  show  that  the  introduction  of  pure  water  supplies  had 
reduced  the  cholera  mortality  in  the  towns  which  had  been 
attacked  by  successive  epidemics.  In.  the  following  table 
the  total  number  of  deaths  given  show  the  decrease  in  the 
mortality  after  the  introduction  of  pure  water  supplies, 
although  in  each  case  the  population  had  increased  rapidly. 


IMPURE   WATER,  ITS  EFFECT  UPON  HEALTH       167 


Year  of  Cholera  Epidemic. 

1832 

1849 

1854 

1866 

Total  deaths  in  Manches- 

ter and  Salford  . 

890 

1,115 

50* 

88* 

Total  do.  in  Glasgow 

2,842 

3,772 

3,886 

68* 

Total  do.  in  Paisley  and 

Charleston 

Not  known 

182 

173 

7* 

Total  do.  in  Hamilton 

63 

251 

44 

2* 

The  most  interesting  of  the  localised  outbreaks  recorded 
is  one  which  occurred  at  Theydon  Bois,  in  Essex,  in  1865. 
A  gentleman  and  his  wife  who  had  been  visiting  at 
Weymouth  returned  home  via  Southampton,  cholera  having 
appeared  in  the  latter  town  eight  days  before.  The  gentle- 
man had  had  an  attack  of  diarrhoea  thirty-six  hours  before 
leaving  Weymouth,  and  had  not  quite  recovered  on  his 
return  home.  The  day  after  their  return  the  wife  was 
attacked  with  diarrhoea,  and  both  used  the  water-closet, 
the  soil  pipe  of  which  was  afterwards  found  to  be  defective. 
The  matters  which  escaped  from  the  soil  pipe  penetrated 
downwards  along  the  outer  wall  of  the  house,  passed 
beneath  the  foundations,  and  saturated  the  earth  in  the 
immediate  vicinity  of  the  well.  Water  poured  down  the 
closet  was  seen  to  commence  dripping  into  the  well  within 
ten  minutes.  This  water  was  used  by  the  family,  and 
within  twelve  days  of  the  specific  pollution,  out  of  the 
twelve  persons  who  drank  the  water,  nine  were  attacked 
with  cholera  of  so  malignant  a  type  that  all  the  cases 
proved  fatal. 

A  number  of  instances  have  been  reported  from  India 
and  elsewhere,  in  which  polluted  water  appears  to  have 
been  the  cause  of  localised  outbreaks.  At  a  jail  near 


*  Indicates  that  prior  to  this  outbreak  the  town  had  substituted  a 
pure  water  supply  for  an  impure  one. 


168  WATER  SUPPLIES 

Poonah  twenty-four  cases  of  cholera  occurred.  Twenty-two 
of  the  sufferers  belonged  to  a  road-gang  who  alone  drank 
water  from  the  Mootla  River.  The  rest  of  the  prisoners 
used  water  laid  on  from  a  lake,  and  only  two  of  these  were 
attacked.  Of  these  two,  one  had  attended  the  cholera 
patients  and  the  other  slept  near  one  of  the  earliest  cases 
during  the  night  when  he  was  attacked  with  vomiting. 
At  Vadakencoulam,  an  outbreak  of  cholera  was  confined  to 
the  higher  castes  who  drank  of  a  polluted  well  water,  whilst 
the  lower  castes  who  used  water  from  other  wells  escaped. 
Many  other  accounts  of  a  similar  character  are  to  be  found 
in  the  Indian  Medical  Gazette  and  in  the  reports  of  Indian 
medical  officers. 

The  epidemic  of  cholera  at  Hamburg  in  1892  was  inter- 
esting in  many  respects.  Just  prior  to  the  outbreak  a 
large  number  of  destitute  Russian  Jews  from  cholera- 
stricken  districts  in  Russia  had  been  encamped  for  a  time  in 
wooden  huts  on  the  quays  of  the  Elbe,  the  sewage  from 
which  passed  into  the  dock  and  would  be  carried  up  the  Elbe 
by  the  rise  of  the  tide,  above  the  intake  of  the  waterworks. 
In  eighty-eight  days  over  18,000  persons  were  attacked  with 
cholera  in  the  city,  and  over  8,000  cases  terminated  fatally. 
Professor  A.  Koch  investigated  this  outbreak,  and  in  a 
paper  on  Water  Filtration  and  Cholera,  he  gives  the  reasons 
which  led  him  to  conclude  that  the  epidemic  was  chiefly  due 
to  the  use  of  imperfectly-filtered  polluted  water.  "  The 
cholera  epidemic  in  the  three  towns  of  Hamburg,  Altona, 
and  Wandsbeck,"  he  says,  "  has  been  in  this  respect 
instructive  in  the  highest  degree.  These  three  towns,  which 
are  contiguous  to  each  other,  and  really  form  a  single  com- 
munity, do  not  differ  except  in  so  far  as  each  has  a  separate 
and  a  different  kind  of  water  supply.  Wandsbeck  obtains 
filtered  water  from  a  lake  which  is  hardly  at  all  exposed  to 
contamination  with  fsecal  matter;  Hamburg  obtains  its 
water  in  an  unfiltered  condition  from  the  Elbe  above  the 
town,  and  Altona  obtains  filtered  water  from  the  Elbe  below 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       169 

the  town.     Whereas  Hamburg  was  notoriously  badly  visited 
by   cholera,   Wandsbeck   and    Altona — if   one   excepts   the 
cases  brought  thither  from  Hamburg — were  almost  quite 
free  from  the  disease.     Most  surprising  were  the  conditions 
of    the    cholera    epidemic    along    the    boundary    between 
Hamburg  and  Altona.     On  both  sides  of  the  boundary  the 
conditions   of   soil,   cultivation,    sewerage,    population, — all 
things,  in  short,  of  importance  in  this  respect, — were  the 
same,  and  yet  the  cholera  in  Hamburg  went  right  up  to  the 
boundary  of  Altona  and  there  stopped.     In  one  street  which 
for  a  long  way  forms  the  boundary  there  was  cholera  on 
the  Hamburg  side,  whereas  the  Altona  side  was  free  from 
it.     Indeed,  in  the  case  of  a  group  of  houses  on  the  so-called 
Hamburger  Platz,   the  cholera  marked  out  the  boundary 
better  than  any  one  having  the  map  of  the  frontier  between 
Hamburg  and  Altona  before  him  could  have  done.     The 
cholera  not  only  marked  the  political  boundary,  but  even  the 
boundary  of  the  water  distribution  between  the  two  towns.* 
The  group  of  houses  referred  to,  which  is  thickly  populated 
by  families  of  the  working  class,  belongs  to  Hamburg,  but 
is  supplied  with  water  from   Altona,   and  remained   com- 
pletely   free    from    cholera;    whereas    all    around    on    the 
Hamburg  territory  there  were  numerous  cases  of  disease 
and  death.     Here  we  have  to  do  with  a  kind  of  experiment 
which  was  performed  on  a  population  of  over  100,000,  but 
which,  in  spite  of  its  immense  proportions,  complied  with  all 
the  conditions  which  one  requires  from  an  exact  and  perfect 
experiment   in    a   laboratory.      In   two   great   populations 
nearly  all  the  factors  are  the  same,  one  only  is  different, 
and  that  the  water  supply.     The  population  supplied  with 
unfiltered    water    from    the    Elbe    is    seriously    visited    by 
cholera ;  the  population  supplied  with  filtered  water  is  only 
visited    by    the    disease    to    a    very    small    extent.     This 

*  Many  of  these  statements  have  since  been  disputed.     Vide  Lancet 
25th  May,  1894, 


i7o  WATER  SUPPLIES 

difference  is  all  the  more  important  as  the  water  of 
Hamburg  is  taken  from  a  place  where  the  Elbe  is 
relatively  but  little  contaminated ;  but  Altona  resorts 
to  the  water  of  the  Elbe  after  it  has  received  all 
the  liquid  and  faecal  refuse  of  800,000  people.  Under 
these  conditions  there  is  no  other  explanation  for 
the  scientific  thinker  but  that  the  difference  in  the 
incidence  of  the  cholera  on  these  two  populations  was 
governed  by  the  differences  in  the  water  supply,  and  that 
Altona  was  protected  against  the  cholera  by  the  filtration 
of  the  water  of  the  Elbe." 

At  a  later  date,  however,  a  small  outbreak  of  cholera  did 
occur  in  Altona;  but  Koch  was  able  to  prove  that  at  this 
time  the  Altona  filters  were  defective  and  allowed  the  infec- 
tious matter  contained  in  the  Elbe  water  to  pass  through. 
The  "  Comma  "  bacillus  had  been  found  in  the  Elbe  water; 
it  was  not  discovered  in  the  imperfectly-filtered  water,  but 
Koch  attributed  this  to  the  small  quantity  of  water  sub- 
mitted to  examination. 

Since  the  discovery  by  Koch  of  the  "  Comma  "  bacillus, 
which  he  and  most  other  observers  consider  to  be  the 
specific  cause  of  cholera,  great  attention  has  been  given  in 
India  and  elsewhere  to  the  detection  of  this  organism  in 
drinking  waters  suspected  of  producing  the  disease.  The 
search  so  far  has  been  very  rarely  successful,  and  at  the 
present  time  the  proof  that  cholera  can  be  disseminated  by 
drinking  water  rests  upon  the  accumulation  of  evidence  of 
cases,  such  as  the  above,  each  failing  in  some  point  as  an 
absolute  demonstration,  but,  taken  collectively,  furnishing 
proof  of  a  most  convincing  character. 

Yellow  Fever. — There  is  little  or  no  evidence  of  this 
disease  being  disseminated  by  polluted  water.  Epidemics 
which  have  occurred  on  board  ship  have  been  attributed  to 
the  decomposition  of  the  organic  matters  in  the  bilge  water, 
and  it  has  been  pointed  out  that  when  yellow  fever  was 
epidemic  in  Gibraltar,  the  drinking  water  was  very  impure ; 


IMPURE  WATER,  ITS  EFFECT   UPON  HEALTH       171 

but  the  relationship  between  the  contaminated  water  and 
the  fever  is  merely  conjectural. 

Oriental  Boils. — In  Syria  and  other  countries,  where  this 
disease  is  prevalent,  there  is  a  general  opinion  that  it  is 
caused  by  drinking  certain  waters.  Various  mineral  sub- 
stances have  been  suspected,  but  there  appears  to  be  very 
little  ground  for  the  suspicion.  Many  Anglo-Indian 
authorities  think  that  some  parasite  may  be  present  in 
such  waters  and  enter  the  skin  when  the  water  is  used  for 
purposes  of  ablution.  Other  forms  of  boils,  ulcers,  and  the 
elephantiasis  of  the  Arabs,  have  been  attributed  to  impure 
waters,  but  the  evidence  is  too  slight  to  render  it  worthy 
of  consideration. 

Diseases  due  to  Animal  Parasites. 

The  study  of  the  life  history  of  many  entozoa  has  proved 
that  certain  stages  of  their  existence  are  passed  in  water ; 
hence  it  at  least  seems  probable  that  such  species  as  infect 
man  and  animals  may  be  introduced  with  the  drinking 
water,  or  may  gain  entrance  through  the  skin  when  water 
infested  with  these  organisms  is  used  for  washing 
purposes  or  for  bathing.  There  is  a  constantly  increasing 
amount  of  evidence  in  support  of  these  theories,  which,  if 
correct,  furnish  additional  proof  of  the  risk  incurred  in 
drinking  impure  water,  especially  in  an  unfiltered  condition. 
The  danger  of  introducing  the  ova  or  larvae  of  these 
parasites  into  the  system  is  one  which  can  be  more  easily 
guarded  against  than  the  introduction  of  the  infinitely  more 
minute  micro-organisms  producing  cholera  and  typhoid 
fever,  since  the  simplest  filtration  will  remove  the  former, 
whilst  the  most  careful  filtration  can  scarcely  be  trusted 
to  remove  the  latter. 

Bacteria  also  may  multiply  indefinitely  within  the  body, 
however  few  the  number  originally  introduced;  but  the 
number  of  immature  or  mature  forms  of  an  entozoon  which 


172  WATER  SUPPLIES 

develop  will  depend  upon  the  number  of  parasites  which 
have  gained  access  to  the  system.  In  the  first  case  the  effect 
upon  the  individual  will  be  practically  uninfluenced  by  the 
number  of  organisms  swallowed,  whilst  in  the  second  the 
effect  will  entirely  depend  upon  and  be  in  direct  relation  to 
the  number  introduced. 

The  entozoa  most  likely  to  infect  man  through  the 
medium  of  drinking  water  are: — Bilharzia  hcematobia, 
Filaria  sanyuinis  hominis,  Dracunculus  mediensis,  and 
Rhabdonema  intestinale,  but  it  is  quite  possible  that 
Filaria  loa  and  many  others  also  gain  access  to  the  system 
in  this  way. 

Bilharzia  hcematolria. — This  entozoon  is  the  cause  of  the 
endemic  hsematuria  so  common  in  Egypt,  Abyssinia,  and 
the  Cape  of  Good  Hope.  The  ova  are  passed  with  the  urine, 
find  their  way  into  water,  and  hatch  into  ciliated  embryos. 
These  probably  pass  through  a  further  stage  of  develop- 
ment in  some  mollusc  or  arthropod,  again  enter  the  water, 
and  are  once  more  ready  to  complete  the  cycle  of  their  life 
history  if  received  into  the  body  of  the  human  host. 
Dr.  Sonsino,  from  his  experience  in  Egypt,  believes  that, 
were  a  rule  made  of  filtering  all  drinking  water,  no  person 
would  become  infested  with  this  parasite.  He  found  the 
disease  almost  entirely  limited  to  the  more  ignorant  portion 
of  the  population  who  use  unfiltered  water.  A  closely-allied 
organism,  believed  to  be  the  cause  of  a  peculiar  form  of 
haemoptysis  in  Japan  and  the  East,  may  also,  judging  from 
analogy,  gain  access  to  the  system  through  the  same 
medium — impure  water. 

Filaria  sanguinis  hominis. — Mosquitoes  derive  the  em- 
bryos of  this  entozoon  from  the  blood  of  infected  persons 
(Manson),  and  the  larvae  develop  in  the  body  of  that  insect. 
These  are  transferred  to  water,  and  thence  again  into  the 
human  body,  either,  as  Manson  conjectures,  by  piercing  the 
skin,  or,  as  is  more  generally  believed,  by  being  swallowed 
either  with  the  drinking  water  or  accidentally  whilst 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       173 

bathing.  This  organism,  which  produces  endemic  hsematuria 
and  chyluria,  occurs  almost  exclusively  within  the  tropics, 
but  affects  all  races  and  nationalities. 

Dracunculus  mediensis  or  Filaria  dracunculus. — The  em- 
bryo of  this  species  is  aquatic  in  habit,  and  according  to 
Fedschenko  it  undergoes  a  further  development  in  the  body 
of  a  cyclops.  In  some  parts  of  India  and  Africa  it  is  said, 
at  times,  to  infect  nearly  half  the  population.  The 
abscesses  to  which  the  fully-developed  worm  gives  rise  being 
most  commonly  found  in  the  feet  and  legs,  and  especially 
about  the  heel,  it  has  been  generally  assumed  that  the 
parasite  enters  through  the  skin,  to  which  it  may  become 
attached  when  bathing,  paddling,  or  walking  barefooted 
over  moist  ground.  Hirsch,  however,  has  collected  a  mass 
of  evidence  proving  that  infection  takes  place  through  the 
medium  of  the  drinking  water.  For  example,  he  records  an 
outbreak  of  dracontiasis  in  1849  amongst  the  members  of 
two  trading  caravans  travelling  from  Bahia  to  Janeiro. 
They  encamped  near  a  stream  and  made  use  of  the  water 
for  drinking,  although  expressly  warned  of  the  consequences 
by  the  natives.  They  did  not  bathe  in  it.  A  few  months 
later  all  the  members  were  affected  with  guinea  worm, 
except  a  negro,  who  was  the  only  one  of  the  party  who  had 
not  drunk  the  water. 

Bhabdonema  intestinale. — Sonsino  states  that  this  para- 
site is  not  quite  so  innocuous  as  is  generally  supposed.  He 
has  seen  cases  of  intense  anaemia  and  of  enteritis  caused  by 
it,  and  he  is  certain  that  it  is  taken  in  with  foul  drinking 
water. 

Ascarides  lumbricoides,  or  common  round  worm.— Experi- 
ments made  to  infect  man  with  the  eggs  of  this  worm  have 
invariably  given  negative  results,  yet  it  seems  probable  that 
one  of  the  ways  in  which  persons  become  affected  is  by  the 
introduction  of  the  parasite  at  some  stage  of  its  develop- 
ment with  the  drinking  water.  Both  in  England  and 
elsewhere  the  .excessive  prevalence  of  lumbrici  has  been 


174  WATER  SUPPLIES 

noted  over  localised  areas  where  the  inhabitants  resorted  to 
polluted  ponds  or  shallow  wells  for  drinking  water. 

Trichoce.phalus  dispar,  or  whip  worm. — Half  the  inhabi- 
tants of  Paris  are  said  to  be  infected  with  this  parasite, 
which,  however,  is  far  more  common  in  the  tropics  than  in 
temperate  climes.  Leuckart  has  proved  that  the  eggs 
passed  with  the  faeces  must  reach  water  or  some  very  damp 
medium  before  the  embryo  can  develop.  If  it  be  now 
introduced  into  the  stomach  with  the  drinking  water,  the 
shell  of  the  egg  is  dissolved  and  the  embryo  liberated. 

Anchylostoma  duodenale. — This  parasite  induces  extreme 
anaemia,  disorders  of  the  intestinal  canal,  haemorrhages,  etc., 
and  causes  great  mortality  in  Brazil,  West  Indies,  and 
Egypt.  During  the  construction  of  the  St.  Gothard  Tunnel 
a  severe  outbreak  of  disease  occurred  amongst  the 
labourers,  who  had  become  infected  by  this  worm.  Isolated 
cases  have  also  been  recorded  in  many  parts  of  Italy,  and 
possibly  in  other  European  countries.  Part  of  its  life 
cycle  is  passed  in  damp  earth,  and  it  has  been  frequently 
observed  that  the  disease  induced  by  it  is  confined  almost 
entirely  to  the  lower  classes,  and  more  especially  to  those 
who  drink  water  from  shallow  pools  and  watercourses. 

Tcenia  echinococcus. — The  hydatid  stage  of  this  tape- 
worm occurs  in  man.  The  tape-worm  itself  develops  in  the 
intestines  of  the  dog,  and  the  ova  passed  may  easily  find 
their  way  into  water,  and  by  this  means  be  introduced  into 
the  human  stomach.  Hydatid  tumours  are  common  in 
Iceland,  parts  of  Australia,  Switzerland,  and  Southern 
Germany. 

Many  other  parasites  which  affect  domestic  animals  are 
taken  in  by  these  animals  when  drinking  excrement- 
polluted  water.  Thus  Distoma  echinatum  is  common  in  the 
duck,  the  Schlerostoma  armatum  or  palisade  worm  causes 
aneurism  in  the  horse,  species  of  Uncinaria  cause  a  form  of 
anaemia  in  dogs,  etc.,  and  all  appear  to  require  water  or 
some  very  moist  medium  in  which  to  pass  through  a 
certain  stage  in  the  cycle  of  their  life  history. 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       175 

The  Effect  upon  Animals  of  drinking  Polluted  Water. — 
This  has  been  but  little  studied,  but  evidence  is  accumulat- 
ing tending  to  prove  that  drainage  from  farmyards  is  not 
quite  so  innocuous  as  is  generally  supposed,  and  that  water 
polluted  with  such  excrement  may  be  a  carrier  of  disease. 
It  would  be  strange  indeed  if  man  alone  were  injuriously 
affected  by  imbibing  such  impurities.     As  the  relation  of 
the   diseases   of   animals   to   those    of   man   become   better 
understood,  it  will  probably  be  found  that  many  specific 
diseases  are   common   to   both,   and   that  the   one   can,   in 
various  ways,  infect  the  other.     Dr.  Vaughan  (Michigan) 
believes  that  animals  may  suffer  from  true  typhoid  fever, 
and  that  he  has  succeeded  in  inducing  the  disease  in  dogs 
and  cats.     If  such  be  the  case,  it  will  explain  the  outbreaks 
of   this   fever   amongst   travellers   in   uninhabited   regions, 
who  have  been  compelled  to  drink  water  fouled  by  wild 
cattle,   and   may   also   account   for   many   of   the   localised 
outbreaks  which  from  time  to  time  occur,  where  the  most 
diligent  inquiry  fails  to  discover  any  specific  pollution  of 
the  suspected  water  by  human  agency.     In  1878,  Dr.  Hicks 
attributed  an  outbreak  of  typhoid  fever  at  Hendon  to  the 
milk  of  certain  cows  who  drank  sewage-contaminated  water 
(Lancet,  1878,  vol.  ii.,  p.  830),  and  since  that  time  other 
observers  have  recorded  outbreaks  which  they  attributed  to 
the  same  cause ;  but  whether  the  milk  itself  was  originally 
infected  or  merely  became  infected  by  the  admixture  with 
specifically  polluted  water  is  still  open  to  question.    In  1889 
Dr.  Gooch  attributed  an  outbreak  of  diphtheritic  tonsillitis 
at  Eton  College  to  the  use  of  milk  from  cows  supplied  with 
filthy   drinking    water   (Brit.   Med.    Journ.,    1890,    vol.    i., 
p.    474).     In    other    similar    cases,    however,    the    milk    is 
believed  to  have  been  specifically  infected  from  sores  upon 
the  teats,  but  even  here  the  possibility  of  the  disease,  of 
which  the  sores  on  the  teats  are  a  symptom,  being  caused 
by  drinking  polluted  water  must  be  admitted. 

In  America,  where  a  considerable  amount  of  attention  has 


i76  WATER  SUPPLIES 

been  paid  to  the  dissemination  of  disease  amongst  cattle  by 
impure  drinking  water,  many  outbreaks  of  anthrax,  hog 
cholera,  glanders,  and  other  diseases  have  been  recorded 
which  competent  observers  attributed  to  this  cause.  On 
one  station  the  carcase  of  an  animal  which  had  died  of 
anthrax  was  cast  into  a  tank  or  pond  from  which  about 
1,000  head  of  cattle  were  supplied  with  water.  Within  a 
very  short  time  10  per  cent,  of  these  died  of  anthrax.  Some 
years  ago,  when  wool  sorters'  disease  appeared  amongst  the 
operatives  at  a  woollen  factory  in  Yorkshire,  a  number  of 
cattle  grazing  in  a  meadow  through  which  flowed  a- stream 
receiving  the  waste  water  from  the  mill,  were  also  attacked. 
In  1893,  many  cattle  on  a  farm  in  South  Russia  died  of 
anthrax,  and  the  bacilli  were  found  in  the  water  used, 
derived  from  a  well.  Professor  P  Frankland  has  shown 
that  under  certain  conditions  the  anthrax  bacillus  forms 
spores  in  water,  and  that  these  spores  retain  their  vitality 
for  a  considerable  period.  Texan  fever,  by  some  patholo- 
gists  regarded  as  a  form  of  anthrax,  is  believed  to  be  spread 
by  the  use  of  water  contaminated  with  the  excreta  of 
infected  cattle. 

Hog  cholera,  a  dysenteric  affection,  is  almost  certainly  a 
water-borne  disease.  The  specific  organism  can  live  for  a 
considerable  time  in  water  and  even  multiply  in  it,  if 
sewage-polluted,  hence  American  observers  are  of  opinion 
that  specifically-contaminated  streams  are  the  most  potent 
agents  in  its  distribution.  Upon  a  farm,  in  Iowa,  where 
chicken  cholera  and  hog  cholera  had  been  prevalent,  the 
dead  animals  were  thrown  into  a  stream.  Shortly  after  a 
number  of  cattle,  horses,  and  sheep  drinking  from  the 
stream  were  affected  with  a  disease  which  invariably  proved 
fatal  after  an  illness  of  about  two  .days'  duration. 

Glanders,  a  specific  infectious  disease,  may  be  transmitted 
from  animal  to  animal  by  the  use  of  a  common  drinking 
trough,  much  as  diphtheria  is  believed  to  be  spread  amongst 
children  by  the  use  of  common  drinking  vessels. 


IMPURE  WATER,  ITS  EFFECT  UPON  HEALTH       177 

That  many  entozoal  diseases,  amongst  cattle,  are 
propagated  by  polluted  waters  can  scarcely  be  doubted,  and 
it  is  quite  possible  that  actinomycosis  may  be  so  caused. 

k  At  the  present  time  no  one  would  contend  that  wate* 
fouled  by  cattle  was  fit  to  be  used  by  man  for  drinking 
purposes,  and  probably  ere  long  proofs  will  be  forthcoming 
that  the  use  of  such  water  by  cattle  is  not  only  inimical  to 
their  health,  but  also  a  source  of  danger  to  the  public 
generally  who  consume  their  milk  and  flesh. 


12 


CHAPTER  X. 

THE  INTERPRETATION  OF  WATER  ANALYSES. 

BY  a  chemical  analysis  the  saline  constituents  of  a  drinking 
water  may  be  ascertained  and  their  quantities  determined, 
and  the  same  applies  also  to  any  sedimentary  matter  which 
the  sample  contains.  Chemical  analysis  also  may  tell  us  of 
the  presence  of  organic  impurity,  but,  as  will  be  seen  in  the 
sequel,  it  can  afford  us  very  little  information  with  regard 
to  its  quality,  and  cannot  even  accurately  measure  the 
quantity.  By  aid  of  the  microscope  the  minute  forms 
of  animal  and  vegetable  life  can  be  detected  and  identified, 
but  the  most  minute  forms,  the  bacteria,  require  a  special 
search  to  be  made  to  determine  their  presence  and 
character. 

In  the  preceding  chapters  on  "  The  Quality  of  Potable 
Waters,"  and  on  "  Diseases  caused  by  Impure  Waters,"  it 
has  been  rendered  evident  that  of  the  many  impurities 
which  drinking  water  may  contain,  the  organic  matter  only 
is  a  serious  source  of  danger,  and  that  by  far  the  greatest 
risk  is  incurred  in  using  waters  liable  to  contain  certain 
living  organisms  which,  when  introduced  into  the  system, 
are  capable  of  producing  specific  disease.  Of  the  presence 
or  absence  of  such  organisms  chemical  analysis  can  give  us 
no  information.  The  presence  of  dead  organic  matter  may 
be  chemically  demonstrated,  but  inasmuch  as  the  nature  of 
this  organic  matter,  whether  poisonous  or  innocuous,  is 
beyond  the  power  of  the  analyst  to  reveal,  it  is  obvious  that 
the  results  of  a  mere  chemical  analysis  may  often  be  worth- 


THE  INTERPRETATION  OF  WATER  ANALYSES       179 

less  or  even  misleading.  This  point  cannot  be  too  strongly 
emphasised,  since  the  popular  impression,  shared  alike  by 
the  ignorant  and  the  learned,  that  a  chemist,  by  performing 
a  few  mysterious  experiments  with  a  water  in  his  labora- 
tory, can  pronounce  at  once  whether  it  be  pure  or  impure, 
safe  or  dangerous,  must  be  dispelled.  This  opinion  has  been 
fostered  by  analysts  who  rarely  hesitate  to  pass  judgment 
upon  a  water  from  the  results  of  their  chemical  examina- 
tion, from  the  determination  of  the  chlorides,  nitrates, 
phosphates,  and  ammonia,  of  the  organic  carbon  and 
nitrogen,  and  of  the  oxygen  consumed,  or  of  the  ammonia 
derivable  from  the  organic  matter.  All  these  factors  are 
of  more  or  less  importance  as  an  index  of  the  degree  of 
pollution,  but  their  real  value  can  in  very  few  cases  be 
assessed  without  some  previous  knowledge  of  the  source  of 
the  water.  The  inorganic  constituents  can  easily  be 
determined,  and  whether,  either  in  quantity  or  quality, 
these  are  objectionable,  the  chemist  can  safely  express  an 
opinion.  Those  only,  therefore,  need  further  be  considered 
which  by  their  presence  tend  to  throw  some  light  upon  the 
source  of  the  organic  matter,  contained  in  greater  or  less 
quantity  in  all  waters.  These  are  the  chlorides,  nitrites, 
nitrates,  ammonia,  and  phosphates ;  and  inasmuch  as  their 
determination  is  often  of  importance,  the  value  of  each 
may  be  discussed. 

Chlorides.— In  the  great  majority  of  instances  the  only 
chloride  present  is  chloride  of  sodium  or  common  salt; 
occasionally  other  chlorides,  as  of  magnesium  and  calcium, 
may  be  found  in  drinking  waters,  but  as  these  are  of  trifling 
significance  they  can  usually  be  disregarded.  Rain  water, 
especially  in  districts  near  the  sea,  always  contains  a  trace 
of  salt.  Certain  geological  formations  are  rich  in  salt, 
and  waters  obtained  therefrom  may  contain  considerable 
quantities.  Urine  also  contains  nearly  1  per  cent. ;  hence 
pollution  with  sewage  will  add  salt  to  the  water.  The 
effluents  from  ma.ny  manufactories,  alkali  works,  mines,  etc., 


i8o  WATER  SUPPLIES 

are  also  rich  in  chlorine.  Prom  these  various  sources, 
therefore,  the  chlorides  found  in  waters  are  derived.  Where 
the  geological  strata  contain  little  or  no  salt,  and  there  are 
no  manufacturing  or  mining  effluents  to  pollute  the  water, 
the  amount  of  chlorides  present  may  serve  roughly  as  an 
index  of  the  extent  to  which  it  has  been  contaminated  by 
sewage.  In  Massachusetts  it  has  been  found  that  the 
amount  of  chlorine  in  the  surface  waters  and  streams 
decreases  in  amount  from  the  seaboard  westward  or  inland. 
By  the  examination  of  waters  from  sources  removed  from  all 
risk  of  contamination,  the  normal  chlorine  for  such  districts 
has  been  determined.  "  By  placing  on  the  map  of  the 
State  the  amount  of  chlorine  *  normally  present  in  its 
unpolluted  waters,  and  then  connecting  the  points  of  equal 
amounts,  lines  of  like  chlorine  contents  are  obtained, 
which  are  called  isochlors."  From  the  map  thus  prepared 
the  normal  chlorine  is  found  to  vary  from  .45  grain  per 
gallon  near  the  coast  to  less  than  .06  in  the  western  part  of 
the  State  (Board  of  Health  Report,  1892).  Over  any  given 
ar.ea,  the  amount  of  chlorine  in  excess  of  the  normal,  as 
above  ascertained,  can  only  be  due  to  the  influence  of  the 
population  discharging  its  sewage  thereupon.  Assuming 
that  100  persons  per  square  mile  add  on  an  average  .03 
grain  of  chlorine  per  gallon  to  the  water  flowing  from  the 
area  considered,  the  extent  of  the  contamination  can  be 
approximately  calculated.  It  must  be  remembered,  how- 
ever, that  the  amount  of  chlorine  present  does  not 
necessarily  signify  present  pollution.  The  organic  matter 
which  originally  accompanied  the  salt,  and  which  alone  is 
deleterious,  may  have  undergone  complete  oxidation  and 
destruction,  so  that  organically  the  water  may  be  very 
pure  although  the  amount  of  chlorine  present  indicates 
that  at  one  time  it  was  excessively  polluted.  This  fact 
detracts  very  considerably  from  the  importance  of  the 

*  I  part  of  chloride  of  sodium  equals  '61  part  of  chlorine. 


THE  INTERPRETATION  OF  WATER  ANALYSES       181 

chlorine  determination.  It  affords  some  evidence  of  the 
previous  history  of  the  water,  and  that  is  all.  In  insular 
countries  the  estimation  of  the  chlorine  is  of  even  less 
value,  since  they  cannot  be  mapped  out  into  isochlors. 
Over  limited  areas,  however,  the  normal  chlorine  may  some- 
times be  ascertained,  and  any  excess  found  in  samples  from 
that  district  will  be  in  a  measure  proportionate  to  the 
present  or  past  pollution  of  the  water.  For  example,  in  the 
parish  of  Writtle  (Table  III.,  p.  57),  the  normal  chlorine 
did  not  exceed  2.5  grains  per  gallon,  yet  in  that  parish  sub- 
soil waters  were  found  containing  as  much  as  14.0  grains  per 
gallon,  and  that  this  was  due  to  past  and  present  pollution 
with  sewage  was  substantiated  by  the  excess  of  other 
substances,  especially  nitrates,  which,  as  we  shall  see,  are 
also  in  \most  cases  derived  from  the  same  source.  Unless 
this  normal  chlorine  be  known,  the  determination  of  the 
chlorides  has  no  value  whatever.  The  variation  in  the 
amount  of  chlorine  in  pure  surface  waters  from  various 
geological  formations  is  given  in  Table  I.  and  any  excess 
over  the  amounts  given  there  would  probably  point  to  past 
or  present  pollution,  and  in  any  case  would  indicate 
that  further  investigation  of  the  source  was  desirable  or 
necessary.  In  shallow-well  waters,  even  when  pure  (Tables 
III.  and  IV.),  the  chlorine  varies  so  greatly  in  amount  that 
it  is  only  in  rare  cases,  as  in  the  one  referred  to  above,  that 
the  determination  affords  any  information  of  value.  In 
spring  waters  also  it  is  difficult  to  decide  upon  the  normal 
chlorine  of  any  particular  formation,  but  if  in  any  case 
the  amount  found  exceeds  the  average,  the  possibility  of 
sewage  pollution  must  be  considered.  The  same  remark 
applies  to  deep-well  waters  (Table  VI.).  If  the  source  of 
the  water  be  not  known,  reliance  upon  the  chlorine  estima- 
tion may  lead  to  serious  error.  I  have  known  an  analyst  of 
repute,  after  examining  one  of  our  Essex  deep-well  waters, 
certify  that  the  large  amount  of  chlorine  indicated  serious 
contamination  with  sewage,  whereas  the  water  was  almost 


i82  WATER  SUPPLIES 

absolutely  pure,  hygienically,  containing  no  organic  matter, 
and  no  excess  of  chlorine  over  that  natural  to  waters  from 
that  particular  source.  In  several  instances,  when  examin- 
ing water  from  these  deep  wells,  I  have  found  the  amount 
of  chlorine  below  the  normal  and  have  sometimes  been  able 
to  prove  that  this  was  due  to  surface  water  (usually  impure) 
having  gained  access  to  the  well.  In  other  cases  a  large 
excess  of  chlorides  has  been  traced  to  the  influx  of  sea 
water.  The  possibility  of  the  excess  of  chlorine  being 
derived  from  manufactories  or  mines  must  also  be 
considered  before  concluding  that  the  water  contains  con- 
taminating matter  of  animal  origin,  and  the  fact  that 
wells  sunk  near  the  sea  shore,  and  near  tidal  rivers,  may 
contain  an  excess  of  chlorides  derived  from  the  infiltration 
of  sea  water  must  not  be  forgotten. 

The  quantity  of  chlorides  present  in  a  water  may  some- 
times be  so  considerable  as  to  raise  the  question  whether 
such  water  is  suitable  for  a  public  supply.  Quite  recently 
I  have  had  to  give  an  opinion  on  this  point.  A  deep 
boring  had  been  made  to  obtain,  from  the  Essex  chalk, 
a  supply  of  water  for  a  small  town.  The  bore  was 
500  feet  deep,  and  the  water  contained  over  70  grains  of 
common  salt  per  gallon.  This  amount  gives  a  distinctly 
perceptible  flavour  to  the  water,  and  I  expressed  the 
opinion  that  this  quantity  was  in  excess  of  what  should 
be  permissible  in  a  public  supply.  The  Local  Govern- 
ment Bo<ard  supported  my  view,  and  a  fresh  source  has  had 
to  be  found.  The  District  Council  made  another  bore 
upon  a  site  suggested  by  me,  and  at  a  depth  of  130  feet 
found  a  much  more  abundant  supply  of  water  containing 
about  half  the  above  amount  of  salt.  From  investiga- 
tions made  in  connection  with  the  above  case  I  came  to 
the  conclusion  that  more  than  50  grains  of  salt  per  gallon 
in  a  drinking  water  was  objectionable,  and  that  70  grains 
should  condemn  it  absolutely.  Little,  however,  is  known 
as  to  the  effect  of  such  a  water  upon  the  health  of  a 


THE  INTERPRETATION  OF  WATER  ANALYSES       183 

community,  and  the  conclusion  I  arrived  at  is  merely  an 
opinion. 

Where  the  chlorides  present  include  magnesium  and 
calcium  chlorides,  much  less  than  the  above  amount 
should  condemn  the  water  as  being  generally  unsuitable 
for  domestic  purposes. 

Nitrates  and  Nitrites. — The  combined  nitrogen  found  in 
drinking  waters  is  contained  in  the  organic  matter, 
ammonia  (NH3),  nitrites  (M'NO2),  and  nitrates  (M'NO3). 
Traces  of  all  three  are  found  in  most  samples  of  rain  water 
(vide  Chap.  II.).  Nitrogenous  organic  matter  undergoing 
putrefaction  invariably  produces  ammonia,  and  by  oxida- 
tion this  ammonia  is  converted,  by  micro-organisms  found 
in  all  soils,  into  water  and  nitric  acid,  the  latter  decom- 
posing the  carbonates  present,  and  forming  nitrates  of  soda, 
potash,  or  lime.  The  ammonia,  however,  is  not  apparently 
converted  directly  into  nitric  acid,  but  passes  through  an 
intermediate  stage,  a  lower  oxide  of  nitrogen,  nitrous  acid 
being  first  formed.  This  process  will  be  described  in 
greater  detail  when  the  purification  of  water  is  being 
discussed.  The  Rivers  Pollution  Commissioners  found  that 
whilst  the  organic  matters  contained  in  sewage,  and  there- 
fore of  animal  origin,  yielded  abundance  of  nitrates  and 
nitrites  by  oxidation  (no  less  than  97  per  cent,  of  the 
combined  nitrogen  of  London  sewage  being  converted  into 
nitrates  by  slow  percolation  through  5  feet  of  gravelly  soil), 
vegetable  matters  yielded  mere  traces  of  these  compounds. 
Upland  surface  waters  "  in  contact  only  with  mineral 
matters,  or  with  the  vegetable  matter  of  uncultivated  soil, 
contain,  if  any,  mere  traces  of  nitrogen  in  the  form  of 
nitrates  and  nitrites;  but  ...  as  soon  as  the  water  comes 
in  contact  with  cultivated  land,  or  is  polluted  by  the 
drainage  from  farmyards  or  human  habitations,  nitrates  in 
abundance  make  their  appearance/'  Subsoil  waters  derive 
their  nitrates  in  part  from  the  oxidised  ammonia  of  rain 
water,  in  part  from  the  slow  decay  of  vegetable  matter,  and 


184  WATER  SUPPLIES 

in  part  from  sewage  matters.  The  amount  derived  from 
the  two  former  is  almost  invariably  small.  Vegetable 
matter  is  not  highly  nitrogenous,  and  as  a  rule  decomposes 
but  slowly.  Animal  matter,  on  the  contrary,  decomposes 
rapidly  and  yields  much  ammonia.  Nitrates  serve  for  the 
food  of  plants,  and  the  active  growth  of  vegetation  may 
remove  nearly  the  whole  of  these  salts  from  a  water.  In 
reservoirs  the  nitrates  decrease  gradually  as  the  vegetable 
organisms  increase.  The  total  combined  nitrogen  therefore 
in  a  water  may  at  one  time  exist  in  decaying  animal  and 
vegetable  matter,  or  in  the  form  of  ammonia ;  at  another  in 
the  form  of  nitrites  and  nitrates,  and  yet  again  as  a 
constituent  of  the  protoplasm  of  living  vegetable  organ- 
isms,— in  which  latter  case  it  is  not  in  solution,  but  merely 
suspended  in  the  water.  Whenever  organic  matter  under- 
goes putrefaction  in  the  absence  of  air  or  free  oxygen,  not 
only  are  nitrates  not  formed,  but  any  nitrates  present  are 
decomposed,  their  oxygen  being  required  for  the  formation 
of  water  and  carbonic  acid  by  combination  with  the  carbon 
and  hydrogen  of  the  decomposing  substances.  The  nitrogen 
appears  to  be  set  free,  possibly  accounting  for  the  excessive 
amount  of  that  element  found  in  such  deep-spring  waters 
as  those  of  Bath,  Buxton,  and  Wildbad.  In  this  way  the 
small  amount  of  nitrates  found  in  most  deep-well  waters  is 
accounted  for.  Such  being  the  case,  it  is  evident  that  even 
concentrated  sewage  may  undergo  such  changes  as  would 
totally  obscure  its  origin  so  far  as  the  combined  nitrogen  is 
concerned.  At  first  this  would  be  contained  chiefly  in  the 
dissolved  animal  impurities;  after  passing  through  the 
surface  soil,  it  would  exist  chiefly  in  the  nitrates  formed 
by  the  oxidation  of  the  organic  matter,  later  the  nitrates 
may  be  decomposed,  and  the  nitrogen  liberated,  when  the 
water  would  be  almost  or  entirely  free  from  combined 
nitrogen.  On  the  other  hand,  certain  deep-well  waters, 
especially  in  the  chalk,  contain  very  considerable  amounts 
of  nitrates,  which  it  is  difficult  to  believe  are  derived  from 


THE  INTERPRETATION  OFiWATER  ANALYSES       185 


the  oxidation  of  sewage  matters.  It  has  been  suggested 
that  these  nitrates  are  derived  from  fossil  remains,  or  from 
natural  deposits  of  nitrates,  or  from  vegetable  matter ;  but 
as  no  proof  of  these  statements  is  forthcoming,  they  must 
be  received  with  reserve.  In  the  eastern  counties  the 
chalk  wells  yield  waters  which  in  some  districts  are  abso- 
lutely free  from  nitrates  (S.E.  Essex),  whilst  in  other 
districts  (Norfolk)  they  may  contain  possibly  as  much  as 
1  grain  of  nitric  nitrogen  per  gallon.  The  following  may 
be  quoted  as  examples. 


Nitric  N. 
per  Gallon. 

Depth  of 
Well. 

Authorities. 

feet. 

Stratford  :  Phoenix  Works 

•00 

200 

J.  C.  Thresh. 

Wimbledon      .... 

•03 

200 

j? 

Chatham  Public  Supply  . 

•48 

490 

» 

Southend            ,, 

•05 

900 

n 

Witham              ,,              . 

•45 

600 

R.P.C. 

Mistley  :    Tendring   Hundred 

W.  W.  Co  

•05 

160 

J.  C.  Thresh. 

Braintree  Public  Supply 

•02 

430 

T.  A.  Pooley. 

Colchester  (Donyland  Brewery) 
Saffron  Walden  Public  Supply 
Norwich  

•00 
•95 

•80 

305 
1000 
About  400 

J.  C.  Thresh. 
» 

In  none  of  the  above  examples  is  there  any  possibility  of 
recent  sewage  contamination. 

Notwithstanding  these  facts  the  Rivers  Pollution  Com- 
missioners considered  the  total  combined  nitrogen  to  be  an 
index  of  previous  sewage  contamination.  They  assumed 
that  100,000  parts  of  average  London  sewage  contains  10 
parts  of  combined  nitrogen  in  solution.  The  mean  amount 
of  such  nitrogen  found  in  a  large  number  of  samples  of  rain 
waters  examined  was  .032  per  100,000.  After  deducting 
this  latter  amount  from  the  amount  of  nitrogen  in  the  form 
of  nitrates,  nitrites,  and  ammonia  found  in  100,000  parts  of 
a  potable  water,  the  remainder,  if  any,  they  say,  "  represents 


186  WATER  SUPPLIES 

the  nitrogen  derived  from  oxidised  animal  matters,  with 
which  the  water  has  been  in  contact.  Thus,  a  sample  of 
water  which  contains,  in  the  forms  of  nitrates,  nitrites,  and 
ammonia,  .326  parts  of  nitrogen  in  100,000  parts,  has 
obtained  .326  -  .032  =  .294  part  of  that  nitrogen  from  animal 
matters.  Now,  this  last  amount  of  combined  nitrogen  is 
assumed  to  be  contained  in  2,940  parts  of  average  London 
sewage,  and  hence  such  a  sample  of  water  is  said  to  exhibit 
2,940  parts  of  previous  sewage  or  animal  contamination  in 
100,000  parts."  The  Rivers  Pollution  Commissioners, 
however,  point  out  that,  on  the  one  hand,  the  nitrates  may 
not  indicate  the  full  extent  of  the  previous  sewage  pollution, 
since  the  roots  of  growing  crops  take  up  much  of  the 
ammonia,  nitrites,  and  nitrates  contained  in  polluted  water, 
and  animal  matter  which  decomposes  without  access  of  air 
destroys  nitrates ;  and,  on  the  other  hand,  that  the  nitrates 
present  may  indicate  10  per  cent,  of  previous  sewage  con- 
tamination in  deep  wells  and  springs,  and  the  risk  of  using 
such  waters  be  regarded  as  nil,  providing  surface  pollution 
be  rigidly  excluded.  This  10  per  cent,  of  previous  sewage 
contamination  corresponds  to  1  grain  of  nitric  nitrogen  per 
gallon. 

Mr.  F.  Wallis  Stoddart,  in  an  excellent  paper  on  "  The 
Interpretation  of  the  Results  of  Water  Analysis,"*  describes 
a  series  of  experiments  in  which  he  passed  sewage  contain- 
ing cholera  bacilli  through  a  nitrifying  bed  of  coarsely- 
powdered  chalk,  and  found  that  although  the  organic 
matter  in  solution  was  completely  nitrified,  yet  the  cholera 
bacilli  or  spirilla  could  be  detected  in  the  effluent.  From 
the  result  of  his  own  observations  and  experiments,  he 
concludes  that  natural  waters  "  can  at  most  obtain  from 
one-tenth  to  two-tenths  of  a  grain  of  nitrogen  as  nitrates 
per  gallon  from  sources  other  than  animal  matter,"  and 
"  that  practically  the  whole  of  the  nitrogen  of  sewage  may 

*  Practitioner,  1893. 


THE  INTERPRETATION  OF  WATER  ANALYSES      187 

be  oxidised  into  nitric  acid  without  materially  diminishing 
the  risk  involved  in  drinking  it."  He  urges  that  whenever 
the  nitrogen  as  nitrates  exceeds  half  a  grain  per  gallon,  it 
indicates  "  either  dangerous  proximity  of  the  well  to  a 
source  of  pollution,  or  such  easy  communication  with  it  that 
the  distance  separating  the  two  points  is  no  guarantee  of 
purification/'  In  the  various  tables  of  analyses  given  in 
previous  chapters  will  be  found  instances  of  many  waters, 
the  source  of  which  I  carefully  examined,  and  which  were 
collected  and  analysed  by  myself,  containing  more  than  this 
amount  of  nitric  nitrogen;  and  I  am  perfectly  convinced 
that  these  waters  are  hygienically  of  the  highest  class,  and 
can  be  used  without  the  slightest  risk  or  danger.  On  the 
other  hand,  in  Table  VII.  there  will  be  found  analyses  of 
many  waters,  containing  very  much  less  nitrogen  as  nitrates, 
which  have  almost  certainly  (in  most  cases  the  proof  was 
very  conclusive)  given  rise  to  outbreaks  of  typhoid  fever. 
If  Mr.  Stoddart's  maximum  of  .5  be  accepted  as  proof  that 
a  water  is  dangerous,  then  the  public  and  private  water 
supplies  of  many  of  our  healthiest  districts — districts  re- 
markably free  from  outbreaks  of  typhoid  fever — must  all 
be  considered  dangerous.  As  a  matter  of  fact  the  amount 
of  nitrates  which  would  condemn  a  water  from  one  source 
may  be  absolutely  without  significance  in  water  from 
another,  all  of  which  goes  to  demonstrate,  as  has  been  pre- 
viously stated,  that  mere  chemical  analysis  is  absolutely 
powerless  to  prove  that  any  water  is  of  such  a  quality  as  to 
be  incapable  of  producing  disease  amongst  those  who 
drink  it. 

Nitrites  may  result  from  the  oxidation  of  ammonia,  or 
from  the  reduction  of  nitrates,  and,  as  they  are  very 
easily  oxidisable,  their  presence  indicates  a  condition  of 
instability,  of  matter  undergoing  change.  Usually  this 
matter  is  of  animal  origin  and  derived  from  manure  or 
sewage,  the  ammonia  produced  by  their  decomposition 
being  in  process  of  oxidation  to  nitrates.  Where  the  soil  is 


i88  WATER1SUPPLIES 

not  sufficient  in  quantity,  or  is  defective  in  quality,  the 
oxidation  may  be  incomplete,  and  incompletely  purified  and 
probably  incompletely  filtered  water  is  the  result.  Usually 
in  such  cases  an  excessive  amount  of  ammonia  is  also 
present.  But  though  usually,  this  is  not  invariably  the 
source  of  the  nitrites  and  ammonia.  Where  nitrates  are 
present  the  nitric  acid  may  be  reduced  by  contact  with 
metals,  such  as  iron  or  lead,  forming  the  pipes  in  which 
the  water  is  conveyed,  or  lining  the  upper  portion  of  the 
well.  Where  such  is  the  case,  a  trace  of  the  metal  can 
always  be  detected  in  the  water.  Unless  this  fact  be 
borne  in  mind — and  it  often  appears  to  be  overlooked— a 
good  and  wholesome  water  may  be  classed  as  dangerous  or 
polluted.  Certain  organisms  also  found  in  water  are  capable 
of  reducing  nitrates  to  nitrites.  Still  the  presence  of 
nitrites  always  renders  a  water  suspicious,  and  their  origin 
should  be  carefully  investigated. 

Ammonia. — All  rain  water  contains  this  compound,  as 
does  also  melted  snow.  The  first  portions  of  a  shower,  and 
the  rain  collected  in  the  neighbourhood  of  towns,  are  richest 
in  ammonia.  As  an  average,  .02  grain  per  gallon,  taken 
by  the  Rivers  Pollution  Commissioners,  is  probably  fairly 
approximate,  but  the  variation  is  very  wide  (.2  to  .01).  In 
passing  over  or  through  the  ground  the  ammonia  is  rapidly 
oxidised,  and  by  the  time  the  water  reaches  a  stream  or  the 
general  body  of  subsoil  water,  most  of  it  has  disappeared. 
Rain  water  stored  in  covered  cisterns,  however,  usually 
retains  its  ammonia  for  a  considerable  period.  In  such 
waters,  therefore,  the  ammonia,  unless  excessive,  is  devoid 
of  significance.  Many  deep-well  waters  also  contain  much 
ammonia,  the  origin  of  which  has  given  rise  to  a  good  deal 
of  surmise.  The  generally  accepted  theory  is  that  it  is  due 
to  the  reducing  action  of  ferruginous  sands  on  the  nitrates 
present.  This  may  be  so  in  some  cases,  but  my  observations 
lead  me  to  believe  that  it  is  often  due  to  the  reduction  of 
the  nitrates  by  the  metal  of  the  bore  tube,  pump  pipe,  and 


THE  INTERPRETATION  OF  WATER  ANALYSES       189 

lining  of  the  well.  I  was  led  to  this  conclusion  from  the 
fact  that  I  found  the  water  from  one  and  the  same  well, 
at  one  time  quite  free  from  ammonia,  and  at  another  con- 
taining as  much  as  one  part  of  ammonia  per  million  parts 
of  water.  In  the  water  containing  ammonia  I  also  found  a 
very  faint  turbidity,  which  cleared  up  on  the  addition  of  a 
little  acid,  and  gave  the  reactions  for  iron.  The  clear, 
ammonia-free  water  also,  when  stored  for  a  time  in  an 
iron  tube  became  turbid,  and  nitrites,  ammonia,  and  iron 
could  be  detected  in  it.  Generally,  however,  the  ammonia 
found  in  river,  spring,  and  well  waters  is  derived  from 
putrescent  animal  matter — that  is,  from  manure  and 
sewage ;  but  before  this  conclusion  can  be  safely  drawn,  the 
other  possible  sources  must  be  excluded.  Dr.  Brown,  in 
his  Report  to  the  Massachusetts  State  Board  of  Health, 
1892,  whilst  agreeing  that  imperfect  oxidation  of  sewage 
matter  is  generally  the  source  of  the  ammonia,  calls 
attention  to  the  fact  that  several  waters  in  the  State  free 
from  such  pollution  contain  a  considerable  amount  of  free 
ammonia.  "  They  are  all  associated  with  iron  oxide  and 
the  fungus  Crenothri.x."  Such  waters  are  found  also  in 
many  swampy  regions,  and  in  wells  sunk  in  ferruginous 
river  silt,  and  usually  become  turbid  from  the  formation 
and  deposition  of  oxide  of  iron  when  exposed  to  the  air. 
The  odour  of  these  waters  is  said  to  be  "  often  disagreeable 
from  dissolved  sulphuretted  and  carburetted  hydrogen." 

Phosphates. — Phosphatic  minerals  are  widely  distributed 
in  nature,  and  traces  may  be  dissolved  by  waters  rich  in 
carbonic  acid.  Albuminous  matters,  whether  of  vegetable 
or  animal  origin,  give  rise  to  phosphates  by  their  decay, 
hence  their  presence,  especially  in  what  the  analyst  may 
conceive  to  be  an  excessive  amount,  has  been  held  to 
indicate  contamination.  The  difficulty  of  detecting  phos- 
phates, when  silica  is  also  present,  as  is  usually  the  case, 
the  still  greater  difficulty  of  estimating  the  quantity,  and 
the  very  doubtful  value  of  the  information  when  obtained, 


igo  WATER  SUPPLIES 

has  caused  most  chemists  to  ignore  their  presence.  Traces 
may  be  found  in  wholesome  waters,  and  their  absence 
affords  no  proof  that  a  water  is  free  from  pollution,  hence 
the  determination  is  useless. 

Organic  Matter. — By  no  known  process  can  either  the 
quantity  or  quality  of  the  organic  matter  in  water  be 
determined.  When  a  known  volume  of  water  is  evaporated 
to  dryness,  the  weight  of  the  residue  is  that  of  the  in- 
organic and  organic  substances  contained  therein.  When 
this  residue  is  ignited  the  organic  matter  is  destroyed  and 
volatilised,  and  the  "  loss  on  ignition  "  has  been  regarded 
as  approximately  expressing  the  weight  of  the  organic 
constituents.  'Such,  however,  is  rarely  thb  case,  since 
carbonic  acid  may  be  driven  off  from  the  carbonates 
present,  and  any  nitrates  present  will  be  more  or  less 
completely  reduced.  Moreover,  some  salts  retain  water 
so  tenaciously  that  the  whole  is  not  driven  off  at  the 
temperature  used  for  drying,  and  this  moisture  is  given 
off  when  the  residue  is  ignited.  For  these  reasons,  chiefly, 
the  "  loss  on  ignition  "  cannot  be  depended  upon  as  an 
index  of  the  amount  of  organic  matter  present.  But 
although  the  total  amount  of  the  animal  and  vegetable 
substances  cannot  be  determined,  the  carbon  and  nitrogen 
therein  can  be  ascertained  by  careful  chemical  analysis. 
Not  only  so,  but  the  authors  of  the  original  process  believed 
that,  with  certain  reservations,  the  proportion  of  the 
nitrogen  to  carbon  indicated  whether  the  organic  material 
was  derived  from  the  animal  or  vegetable  kingdom.  In 
fresh  peaty  water  the  Rivers  Pollution  Commissioners  found 
that  N:  0  =  1: 11. 93,  whilst  in  similar  waters,  which  had 
been  stored  for  weeks  or  months  in  lakes,  N:  0=1:5.92. 
After  such  water  had  been  filtered  through  porous  strata, 
N:C=1:3.26.  In  fresh  sewage  the  average  of  a  large 
number  of  samples  gave  N :  0=1  :  2.1.  Highly  polluted  well 
waters,  soakage  from  cesspools,  etc.,  gave  N:  0  =  1:3.126. 
In  sewage  after  filtration  through  soil  the  proportion  of  N 


V  OF  THE 


THE  INTERPRETATION  OF  WATER  ANALYSES       191 

to  C  rose  from  1:1.8  to  from  1:4.9  to  1:7.7.  Evidently 
therefore  the  ratios  of  N  to  C  "  in  soluble,  vegetable,  and 
animal  organic  matters  vary  in  opposite  directions  during 
oxidation,  —  a  fact  which  renders  more  difficult  the  decision 
as  to  whether  the  organic  matter  present  in  any  given 
sample  of  water  is  of  animal  or  vegetable  origin." 

All  nitrogenous  organic  matter,  whether  of  vegetable  or 
animal  origin,  yields  more  or  less  ammonia  when  boiled 
with  a  strongly  alkaline  solution  of  permanganate  of 
potash,  and  the  ammonia  so  yielded  by  potable  waters  is 
called  "  albuminoid,"  or  "  organic  "  ammonia.  The  pro- 
portion of  nitrogen  in  the  ammonia  so  yielded  to  the  total 
nitrogen  in  the  organic  matter  is  unfortunately  not  con- 
stant ;  but  the  chemists  to  the  Massachusetts  Board  of 
Health  believe  that  when  the  process  is  performed  as  in 
their  practice,  about  one-half  the  nitrogen  is  converted 
into  ammonia.  Albuminoid  substances  of  animal  origin 
contain  about  16  per  cent,  of  nitrogen,  but  vegetable 
matters  contain  very  much  less;  hence  the  amount  of 
"  albuminoid  "  ammonia  is  no  index  to  the  amount  of 
organic  matter  present  in  the  water.  Professor  Wanklyn, 
who  devised  this  process,  considers  that  undeniably  con- 
taminated waters  always  yield  an  excessive  amount  of 
albuminoid  ammonia  (over  .10  part  per  million);  usually 
with  much  free  ammonia  (over  .08  part  per  million).  If 
the  albuminoid  ammonia  distils  over  very  slowly  and  is  in 
excess,  but  the  water  contains  little  free  ammonia  and  very 
small  quantities  of  chlorides,  Professor  Wanklyn  considers 
this  an  indication  that  the  contaminating  matter  is  of 
vegetable  origin.  He  adds  :  "  The  analytical  characters, 
as  brought  out  by  the  ammonia  process,  are  very  distinctive 
of  good  and  bad  waters,  and  are  quite  unmistakable."  The 
generally  accepted  opinion,  however,  is  that  no  reliance  can 
be  placed  upon  these  determinations  taken  alone,  and  in  the 
Massachusetts  State  Board  of  Health  Report  for  1890 
there  is  quoted  as  an  example  the  results  of  the  analyses. 


i92  WATER  SUPPLIES 

of  certain  of  the  Boston  water  supplies.  Reservoir  No.  4 
is  known  to  contain  the  purest  water,  but  the  average 
"  albuminoid "  ammonia  during  two  years  was  .26  per 
million.  The  water  of  the  Mystic  Lake  is  the  worst  of  the 
Boston  waters,  since  it  contains  both  sewage  and  manu- 
facturing refuse ;  yet  during  the  same  period  the  average 
albuminoid  ammonia  was  exactly  the  same  as  in  the  purer 
water.  In  the  table  given  below  many  other  examples 
will  be  found  of  the  erroneous  conclusions  which  may  be 
drawn  from  a  too  implicit  reliance  upon  the  determination 
of  the  ammonia  yielded  by  distillation  with  alkaline 
permanganate. 

Forschammer  devised  a  process  for  the  estimation  of  the 
amount  of  oxygen  required  to  oxidise  the  organic  matter 
in  water.  This  method,  as  improved  by  the  late  Dr.  Tidy, 
has  become  very  popular,  and  many  attempts  have  been 
made  to  render  the  results  comparable  with  those  obtained 
by  Frankland's  process,  in  which  the  amount  of  organic 
carbon  and  nitrogen  is  ascertained  by  combustion,  but 
with  only  partial  success.  The  results,  when  compared 
with  those  obtained  by  the  "  albuminoid  ammonia  "  pro- 
cess, show  no  constant  relation  between  the  amount  of 
ammonia  yielded  by  a  water  when  distilled  with  an  alkaline 
solution  of  permanganate  of  potash,  and  the  amount  of 
oxygen  absorbed  when  the  same  water  is  digested  with  an 
acid  solution  of  the  same  salt.  This  process  tells  us  little 
or  nothing  of  the  nature  of  the  polluting  material ;  it  does 
not  even  distinguish  between  organic  matter  of  vegetable 
and  animal  origin,  and  it  affords  us  no  evidence  of  the 
amount  of  such  substances  present.  Certain  bodies  of 
mineral  origin  often  found  in  water  (sulphuretted  hydrogen, 
nitrites,  the  lower  oxides  of  iron,  etc.)  also  absorb  oxygen, 
and  unless  great  care  is  taken  to  ascertain  the  absence  of 
these,  or  to  ascertain  the  exact  amount  of  oxygen  consumed 
by  them  if  present,  serious  errors  may  be  introduced. 
When  these  corrections  are  made  the  oxygen  process  is 


THE  INTERPRETATION  OF  WATER  ANALYSES       193 


still  open  to  all  the  objections  which  have  been  urged 
against  the  albuminoid  ammonia  process.  It  may  condemn 
a  perfectly  harmless  water  as  polluted,  and  pass  as  of  good 
quality  a  water  of  most  dangerous  character.  The  follow- 
ing table  was  devised  by  Drs.  Tidy  and  Frankland. 

AMOUNT  OF  OXYGEN  ABSORBED  BY  1,000,000  PARTS  OF  WATER. 


Upland  Surface 
Water. 

Water  other  than 
Upland  Surface 
Water. 

Water  of  great  organic  purity 
„         medium  purity 
,,         doubtful  purity 
Impure  water 

Not  more  than  1-0 
3-0 
4-0 
More  than  4-0 

Not  more  than  '5 
1-5 
2-0 
More  than  2-0 

When  the  quality  of  a  water  is  considered  from  the 
biological  side  instead  of  the  chemical,  the  absurdity  of 
dividing  waters  into*  classes  of  pure,  medium,  doubtful 
purity,  and  impure,  is  obvious.  A  water  containing  a 
poisonous  quantity  of  typhoid  bacilli  might  upon  analysis 
be  brought  within  any  of  these  classes,  according  to  the 
quantity  and  quality  of  the  accompanying  impurities. 
In  the  analyses  given  below  there  are  instances  of  waters 
coming  within  Tidy's  limit  of  "  great  organic  purity,"  yet 
which  proved  to  be  capable  of  causing  disease.  I  have 
examined  many  such  waters  myself,  and  have  also  passed 
many  waters  as  perfectly  safe  for  domestic  purposes  which 
a  mere  reference  to  the  above  standards  would  have 
condemned  as  doubtful  or  impure. 

Many  other  special  processes  for  determining  whether  a 
water  be  safe  or  dangerous  have  been  devised,  but 
inasmuch  as  they  are  rarely  used,  it  may  safely  be  inferred 
that  they  possess  no  advantage  over  those  to  which  we 
have  already  referred. 

Whilst  no  single  determination  will  enable  the  analyst 
to  certify  that  a  water  is  free  from  danger,  or  that  it  is  so 
polluted  as  to  be  dangerous  to  health,  the  determination 

13 


ig4  WATER  SUPPLIES 

of  several  constituents  may  enable  him  to  pronounce  it  to 
be  polluted  and  dangerous,  but  will  never  justify  him  in 
certifying  that  it  can  be  used  absolutely  without  risk.  As 
the  freedom  from  all  dangerous  polluting  material  is  the 
information,  usually  sought  from  the  analyst,  it  follows 
that  if  this  cannot  be  ascertained  by  analysis,  a  chemical 
examination  is  in  most  cases  quite  useless.  Where  a  water 
is  known  to  be  contaminated  with  sewage,  or  known  to  be 
liable  to  such  pollution,  an  analysis  is  superfluous.  When 
we  also  consider  that  many  sources  of  supply  are  only 
subject  to  intermittent  pollution,  and  that  waters  from  the 
same  reservoir  or  from  the  same  well  (vide  Analyses 
Nos.  24,  25,  and  26,  27)  may  vary  considerably  in  com- 
position, according  to  the  depth  from  which  the  samples 
are  taken,  the  character  of  the  season,  etc.,  it  is  obvious 
that  the  chemical  examination  of  a  water  is  a  matter  of 
comparatively  '  trifling  importance  compared  with  the 
thorough  examination  of  its  source  and  an  accurate  know- 
ledge of  its  history.  Frequently  waters  are  sent  for 
analysis,  and  the  analyst  is  wilfully  kept  in  ignorance  of 
their  origin  lest  the  information  should  prejudice  his 
report,  yet  without  this  knowledge  he  is  not  justified  in 
expressing  an  opinion  whether  any  water  can  be  used  with 
safety.  In  commenting  upon  a  recent  paper  in  which  I 
expressed  these  views,  a  writer  in  the  Chemist  and  Druggist 
says :  "It  would  seem,  therefore,  that  we  are  face  to  face 
with  the  question,  '  Is  water  analysis  a  failure  ?  '  It  has 
been  so  exclusively  the  province  of  chemical  analysts  to 
pronounce  judgment  upon  domestic  waters,  and  they 
generally  have  given  so  little  attention  to  the  large  issues 
attached  to  analysis,  and  so  very  much  to  sets  of  standard 
figures  for  chlorine,  nitrogen,  hardness,  and  so  on,  that  the 
attack  from  the  medical  health  side  is  not  unexpected. 
There  has  been  more  wrangling  over  water  analyses  than 
over  anything  else  in  chemistry — and  for  what?  Some 
figure  in  the  second  or  third  place  of  decimals,  probably, 


THE  INTERPRETATION  OF  WATER  ANALYSES       195 

and  in  regard  to  what  this  ammonia  or  that  ammonia 
implies,  when  a  visit  to  the  source  of  the  water,  and  an 
inspection  of  the  sewage  trickling  into  it  might  settle 
everything.  That  is  what  Sir  George  Buchanan  and  Dr. 
Thresh  advocate."  The  Royal  Commission  on  Metropolitan 
Water  Supply  received  evidence  proving  that  waters  con- 
taining very  large  amounts  of  organic  matter  were  drunk 
continuously  by  a  population  with  perfect  impunity,  whilst 
other  waters  containing  so  little  organic  matter  as  almost 
to  defy  chemical  detection  had  proved,  time  after  time, 
to  be  of  the  most  poisonous  character.  For  these  reasons 
they  conclude  that  the  water  question  has  passed  from  the 
domain  of  chemistry  into  that  of  biology.  This,  however, 
is  not  strictly  correct.  The  biological  problems  involved 
in  the  investigation  of  water  supplies  are  numerous  and 
complex,  and  as  yet  but  imperfectly  understood. 

Although  a  mere  analysis  cannot  guarantee  us  purity  and 
safety,  yet  it  very  frequently  can  reveal  to  us  impurity  and 
risk.  When  the  source  of  a  water,  upon  most  careful 
examination  by  an  expert,  is  found  to  be  free  from  all 
danger  of  pollution,  and  the  chemical  examination  proves 
that  the  inorganic  constituents  are  unobjectionable  both  in 
quantity  and  quality,  and  that  organic  matter  is  absent  or 
present  in  barely  appreciable  amount,  then  safety,  so  far 
as  human  foresight  can  be  trusted,  may  be  guaranteed. 
If  organic  matter  be  present  in  appreciable  quantity — 
that  is,  if  the  water  yield  such  a  quantity  of  organic 
nitrogen  and  carbon,  or  albuminoid  ammonia,  or  requires 
such  an  amount  of  permanganate  for  oxidation  as  to  render 
it  of  suspicious  or  of  doubtful  purity — a  study  of  the 
history  of  the  water  and  of  its  geological  source  may,  and 
generally  does,  enable  an  opinion  to  be  formed  as  to  the 
nature  of  the  organic  matter,  and  as  to  whether  it  is  of  an 
innocuous  or  dangerous  character.  Chemical  analysis, 
therefore,  has  its  use ;  it  is  only  when  it  is  made  the  sole 
arbiter  between  safety  and  risk  that  it  is  abused,  and  is 


ig6 


WATER  SUPPLIES 


pq 


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THE  INTERPRETATION  OF  WATER  ANALYSES       197 


p    :     <N      -*  T^H  p  cp    :    :    :    :    :    :i>-     ^      ^'P 

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O      O  PQ      ft  t>S 


ig8  WATER  SUPPLIES 

liable  to  lead  to  errors  fraught  with  most  disastrous 
consequences.  Let  the  analysis  be  as  careful  and  complete 
as  possible,  but  let  the  results  always  be  interpreted  in  the 
light  afforded  by  a  searching  examination  of  the  source  of 
the  sample.  Let  all  so-called  standards  be  abandoned  as 
absurd,  and  let  the  opinion  as  to  whether  a  water  is 
dangerous  or  safe  be  based  upon  a  full  consideration  of 
other  and  more  important  factors. 

In  the  foregoing  table  the  erroneous  conclusions  which 
may  be  deduced  from  a  too  great  dependence  upon 
analytical  data  are  fully  exemplified. 

Remarks. 

1.  Analysis  of  water  from  the  river  Ouse  below  where  it 

receives  the  sewage  of  Buckingham.  Examined  for 
the  Town  Council,  29th  February,  1888,  by  W.  W. 
Fisher,  Public  Analyst.  Report — "  Does  not  appear 
from  the  analysis  to  contain  sewage  matters." 
Quoted  by  Dr.  Parsons  in  his  report  to  Local 
Government  Board  on  an  outbreak  of  enteric  fever 
in  1888,  as  a  "  further  illustration  of  the  inability 
of  a  chemist  to  prove  the  quality  of  organic  matter 
in  water  when  its  quantity  is  small." 

2.  Analysis  of  the  Buckingham  public  water  supply  by 

Mr.  Fisher.  Certified  by  him  to  be  a  first-class 
water,  yet  believed  by  Dr.  Parsons  to  have  been 
the  cause  of  the  above  outbreak. 

3.  Analysis  of  the  Beverley  water  supply  from  borings 

in  the  chalk,  by  Mr.  Baynes,  18th  July,  1884.  In 
1884  an  outbreak  of  typhoid  fever  occurred  here, 
and  was  investigated  for  the  Local  Government 
Board  by  Dr.  Page.  The  evidence  led  him  to 
conclude  that  the  specific  contamination  of  the 
water  supply  was  the  immediate  cause  of  the  out- 
break, The  water  had  been  repeatedly  analysed. 


THE  INTERPRETATION  OF  WATER  ANALYSES       igg 

and  the  analysis  given  was  made  "  on  the  very 
border  of  the  period  when  the  water  was  acting 
as  the  epidemic  agent."  It  was  certified  to  be  "  of 
a  very  high  degree  of  purity,  and  eminently  suitable 
for  drinking  and  domestic  purposes/'  Specifically 
infected  sewage  from  an  asylum  had  been  spread 
upon  land  near  the  well  and  reservoir. 

4,  5.  Analyses  of  water  from  the  much  polluted  Trent  at 
(4)  Torksey,  and  (5)  Knaith,  by  Dr.  Tidy,  20th 
December,  1890.  The  analyst  reported  that  "  there 
is  no  evidence  of  the  product  of  sewage  contamina- 
tion." From  Dr.  Bruce  Low's  Report  to  the  Local 
Government  Board,  on  the  occurrence  of  enteric 
fever  amongst  the  population  using  the  Trent 
water,  1893. 

6.  Analysis  of  the  well  water  supplying  Hough  ton-le- 
Spring,  24th  April,  1889.  Early  in  the  month  a 
sudden  outbreak  of  typhoid  fever  occurred  here, 
and  a  sample  of  the  water  (was  at  once  sent  for 
analysis.  The  analyst  reported :  "  This  water  is 
very  free  from  indication  of  organic  impurity.  .  .  . 
It  is  a  good  water  for  drinking  purposes."  Dr. 
Page,  who  investigated  this  outbreak  for  the  Local 
Government  Board,  found  that  sewage  from  a  farm 
three-quarters  of  a,  mile  away  was  discharging  into 
the  well  at  a  point  45  feet  from  the  surface. 

7-14  form  a  very  interesting  series  of  analyses  by  chemists 
of  the  highest  repute,  of  the  Tees  water  as  supplied 
to  the  towns  in  the  Tees  valley.  Two  outbreaks  of 
enteric  fever  occurred  in  these  towns,  the  first 
between  7th  September  and  18th  October,  1890; 
and  the  second  between  28th  December,  1890,  and 
7th  February,  1891.  Dr.  Barry  reported  upon  them 
to  the  Local  Government  Board.  He  found  the 
river  above  the  intake  of  the  Water  Companies 
excessively  polluted  by  sewage,  cesspool  drainage, 


200  WATER  SUPPLIES 

etc.  It  is  with  reference  to  the  relation  of  this 
water  to  the  typhoid  epidemics  that  Dr.  Thorne 
says :  "  Seldom,  if  ever,  has  the  proof  of  the  relation 
of  the  use  of  the  water  so  befouled  to  wholesale 
occurrence  of  typhoid  fever  been  more  obvious  or 
patent."  The  analyses  now  quoted  were  made 
before,  during,  and  after  the  epidemic  periods,  yet, 
as  will  foe  seen,  in  not  a  single  instance  did  the 
chemical  examination  indicate  either  pollution  or 
danger. 

7.  Analysis  of  the  Middlesborough  water  supply  by  Dr. 

Frankland,  F.R.S.,  23rd  August,  1890.  Report— 
"  Peaty  .  .  .  but  in  all  other  respects  the  water  is  of 
excellent  quality  for  domestic  use,  and  it  is  free 
from  any  trace  of  sewage  contamination" 

8.  Ditto.,    23rd    October,    1890.      Report—"  With    the 

exception  of  a  peaty  taste,  it  is  in  all  respects  of 
excellent  quality  for  dietetic  and  all  other  domestic 
purposes/' 

9.  Analysis  of  the  Middlesborough  water  supply  by  A.  H. 

Allen,  F.I.C.,  27th  October,  1890.  Report— The 
results  "  negative  any  suspicion  of  contamination 
by  sewage  or  cesspool  drainage.  .  .  .  No  suspicious 
results  were  obtained  on  bacteriological  and  other 
microscopical  examination." 

10.  Analysis    of    the    Middlesborough    water    supply    by 

Messrs.  Pattinson  and  Stead,  29th  October,  1890. 
Report — "  Perfectly  wholesome  and  free  from  any 
sewage  contamination.  .  .  .  The  microscope  reveals 
nothing  of  an  objectionable  character." 

11.  Analysis  of  the  Darlington  water  supply  by  F.  K. 

Stock,  County  Analyst,  2nd  December,  1890. 
Report — "  I  have  no  hesitation  in  saying  that  the 
Tees  water,  as  at  present  being  supplied  to  con- 
sumers, is  of  good  and  wholesome  quality." 

12.  Analysis  of  the  Middlesborough  water  supply  by  Dr. 


THE  INTERPRETATION  OF  WATER  ANALYSES       201 

Frankland,  F.R.S.,  1st  January,  1891.  Report— 
"  Of  excellent  quality  for  dietetic  and  all  domestic 
purposes/' 

13.  Analysis    of    Darlington    water    supply    by    F.    K. 

Stock,  County  Analyst,  9th  February,  1891.  "I 
am  of  opinion  that  Tees  water,  as  supplied  to  the 
town  on  29th  January,  1891  (the  date  when  the 
sample  was  taken),  was  good  and  wholesome  drink- 
ing water." 

14.  Analysis    of   the    Stockton   water   supply   by    A.    C. 
Wilson,  Borough  Analyst,  August,  1891.     Report — 
"  Heavily  charged  with  organic  matter  of  vegetable 
origin ;   there  is,  however,  no  appearance  of  animal 
pollution." 

That  the  river  Tees  some  miles  above  the  Company's 
intake  is  grossly  polluted  with  sewage,  no  one  has 
denied,  yet  these  waters,  upon  analysis,  were  said  to 
be  pure  and  wholesome,  and  free  from  any  trace  of 
sewage  contamination.  As  they  are  stated  by  the 
most  competent  authorities  to  have  been  the  cause 
of  the  extensive  epidemics  of  typhoid  fever,  most 
of  them  must  have  been  absolutely  poisonous  at  the 
time  they  were  examined. 

15.  16.  In    1887,    when    an   inquiry    was    being   held   to 

investigate  the  pollution  of  the  river  Tees,  the  late 
Professor  Tidy  examined  a  number  of  samples  of 
water  therefrom.  No  15  is  the  mean  of  several 
analyses  of  samples  taken  above  where  the  river 
receives  the  sewage  of  Barnard  Castle,  and  No.  14  is 
the  mean  of  several  analyses  of  samples  taken  at 
Darlington,  15  miles  below  Barnard  Castle.  Not- 
withstanding the  sewage  poured  in  at  this  town,  and 
at  points  nearer  Darlington,  Dr.  Tidy  reported  that 
the  water  at  the  latter  place  was  rather  better  than 
at  the  former,  and  was  good  and  wholesome.  He 
adds :  "I  am  of  opinion  that  if  the  quantity  of 


2  WATER  SUPPLIES 

sewage  discharged  into  the  river  at  Barnard  Castle 
was  enormously  greater  than  at  present,  the  self- 
purifying  action  of  the  water  would  be  amply 
sufficient  to  oxidise  every  trace  of  sewage  impurity 
within  a  short  distance  of  the  outfall.  Further,  I 
am  of  opinion  that  Darlington  would  not  be  pre- 
judiced (although  the  river  is  the  source  of  the 
water  supply)  even  if  an  outbreak  of  fever  or  cholera 
were  to  occur  at  Barnard  Castle." 

17.  Mean  of  four  analyses  of  the  Mountain  Ash  water 

supply  (spring  and  surface  water)  by  Dr.  Dupre, 
November,  1887.  A  serious  outbreak  of  typhoid 
fever  occurred  here,  commencing  in  July,  1887,  and 
continuing  until  October.  Mr.  John  Spear  investi- 
gated it  for  the  Local  Government  Board,  and 
attributed  the  epidemic  to  insuction  of  filth  into 
one  of  the  water  mains  during  intermission  of  the 
service.  Dr.  Dupre  found  the  samples  almost 
identical  from  a  chemical  point  of  view,  and  very 
pure  and  free  from  any  indication  of  sewage  pollu- 
tion. The  two  samples,  however,  which  were  taken 
from  the  taps,  after  six  hours'  intermission,  were 
found,  when  examined  microscopically,  to  contain 
fungoid  growths  and  large  animalcule  which  were 
absent  from  the  two  other  samples. 

18-23  are  analyses  quoted  from  the  Reports  of  the 
Massachusetts  State  Board  of  Health,  1890-92. 

18.  A  sample  of  unpolluted  surface  water  containing  less 

nitrates  and  yielding  more  albuminoid  ammonia 
than  (19),  a  sample  of  surface  water  known  to  be 
polluted  by  sewage. 

20.  The  average  of  a  series  of  monthly  examinations  of 
the  water  of  the  Merrimac  River,  supplying  the 
town  of  Lowell  during  1891,  when  typhoid  fever 
was  epidemic,  and  attributed  to  the  water  being 
specifically  infected  nine  miles  above  the  intake, 


THE  INTERPRETATION  OF  WATER  ANALYSES       203 

21.  Analysis  of  water  from  the  Chicopee  River  supply- 

ing the  city  of  Chicopee.  Specific  pollution  is 
believed  to  have  taken  place  seven  miles  above  the 
intake,  and  to  have  caused  an  outbreak  of  typhoid 
fever  in  the  city. 

22.  Analysis  of  the  water  from  No.  4  reservoir,  the  purest 

of  the  four  water  supplies  to  the  city  of  Boston, 
and  (23)  of  the  water  from  Mystic  Lake,  the  most 
impure  supply,  showing  that  the  albuminoid 
ammonia  yielded  by  the  latter  does  not  exceed 
that  yielded  by  the  former. 

24,  25  are  waters  from  a  deep  well  in  Essex ;  (24) 
collected  during  dry  weather ;  (25)  collected  eighteen 
hours  after  very  heavy  rain.  This  well  water  is 
liable  to  most  serious  pollution,  yet  a  report  based 
merely  upon  the  results  of  the  first  analysis  would 
most  certainly  have  been  favourable. 

26,  27  are  waters  taken  by  me  from  the  same  well ;  26 
from  near  the  surface,  and  27  from  near  the  bottom. 

28,  29,  30.  Analyses  of  waters  from  bored  wells  in  the 
chalk  supplying  the  Suffolk  County  Asylum.  From 
a  Report  by  Dr.  George  Turner  on  an  outbreak  of 
dysentery. 

28,  29.  These  samples  were  taken  from  the  same  well 
(350  feet  deep),  the  first  on  llth  October,  1893,  and 
the  other  ten  days  later.  The  difference  in  the 
amount  of  chlorine  is  most  marked,  and  led  Dr. 
Turner  to  conclude  that  the  lining  of  the  bore  was 
defective,  admitting  subsoil  water.  Sample  28 
corresponds  closely  with  No.  30,  which  was  taken 
from  a  second  bored  well,  305  feet  deep,  and  only 
16  feet  from  the  first  well.  Waters  28  and  30  are 
probably  free  from  admixture  with  subsoil  water. 
That  such  water  gained  access  to  the  well  from 
which  Nos.  28  and  29  were  taken  was  proved  by 
digging  a  hole  near  the  bore  and  pouring  into  it  a 


204  WATER  SUPPLIES 

quantity  of  solution  of  chloride  of  lithium.  Two 
days  later,  lithia  could  be  detected  in  the  water 
pumped  from  the  bore  tube.  No.  29  is  an  example 
of  an  impure  disease-producing  water,  containing 
less  chlorides  and  absorbing  less  oxygen  than  an 
unpolluted  water  from  the  same  source. 
31.  Upon  this  meagre  analysis  this  water,  derived  from 
a  deep  boring  in  the  chalk,  was  condemned,  and  the 
analyst  said  that  it  could  not  possibly  be  derived 
from  the  chalk.  As  a  matter  of  fact  the  water  was 
exceptionally  pure,  and  typical  of  the  deep  chalk 
waters  of  the  district.  Quite  a  number  of  instances 
have  come  under  my  observation  in  which  good 
waters  have  been  condemned  as  sewage-polluted  by 
analysts  who  were  ignorant  of  the  character  of  the 
water  derived  from  particular  strata. 

With  the  discovery  of  the  fact  that  such  diseases  as 
typhoid  fever  and  cholera  are  due  to  the  introduction  into 
the  system,  not  of  dead  organic  matter,  but  of  actual  living 
organisms,  faith  in  the  chemical  analysis  of  waters  began 
to  be  shaken.  When  still  more  recently  the  actual 
microbes  causing  these  diseases  had  been  identified,  and 
processes  were  said  to  have  been  devised  for  isolating  them 
from  the  multitude  of  other  organisms  found  in  water,  it 
seemed  as  though  the  examination  of  water  for  sanitary 
purposes  had  passed  from  the  domain  of  the  chemist  to 
that  of  the  bacteriologist.  The  study  of  the  number  and 
character  of  the  bacteria,  it  was  hoped,  would  enable  the 
biologist  to  definitely  pronounce  whether  a  certain  water 
was  capable  of  causing  disease,  or  whether  it  was  perfectly 
harmless  in  character.  Up  to  the  present  time  such  hopes 
have  not  been  fully  realised,  and  the  results  of  an  ordinary 
bacteriological  examination  may  be  as  misleading  as  those 
of  a  chemical  analysis.  The  reason  for  this  is  not  difficult 
to  explain,  when  the  significance  of  certain  of  the  dis- 


THE  INTERPRETATION  OF  WATER  ANALYSES       205 

coveries  made  by  bacteriologists  is  thoroughly  understood. 
An  enormous  number  of  species  of  bacteria  have  already 
been  discovered,  although  the  science  is  in  its  infancy. 
They  are  almost  ubiquitous,  abounding  in  the  air,  water, 
and  nearly  all  articles  of  food  and  drink.  Of  this  immense 
variety  very  few  appear  to  be  capable  of  causing  disease ; 
the  remainder  are  perfectly  harmless  to  human  beings, 
whilst  many  are  already  known  to  discharge  most  im- 
portant functions  in  the  economy  of  nature.  Upon  their 
presence  the  fertility  of  soil  in  a  great  measure  depends; 
they  break  down  the  dead  organic  matter  into  the  simpler 
forms  which  can  be  assimilated  by  the  roots  of  plants.  By 
their  action  the  foul  organic  constituents  of  polluted  water 
are  converted  into  carbonic  and  nitric  acid,  which,  in 
combination  with  the  mineral  bases  form  innocuous 
carbonates  and  nitrates.  They  are,  in  fact,  nature's 
scavengers,  consuming  the  foul  and  effete,  and  producing 
therefrom  matters  of  a  harmless  character. 

The  microbes  found  in  water  are  chiefly  bacilli.  Micro- 
cocci  are  comparatively  rare,  whilst  spirilla  are  not 
uncommon,  especially  in  polluted  waters.  Already  over 
200  distinct  species  of  microbes  have  been  discovered  in 
potable  waters,  and  amongst  these  are  several  which  are 
pathogenic  or  disease  producing.  According  to  Professor 
Percy  Frankland,*  these  are — 

Typhoid  bacillus 

Cholera  spirillum,  or  "  comma  bacillus  " 

Tetanus  bacillus 

Anthrax       „ 

Tubercle 

Bacillus  brevis 

,,        capsulatus 

,,        proteus  fluorescens 

,,        coli  communis 

*  Journal  of  State  Medicine,  January,  1894.  "  The  Bacteriological 
Examination  of  Water." 


2o6  WATER  SUPPLIES 

Bacillus  hydrophilus  fuscus 

„        pyocyaneus 
Staphylococcus  pyogenes  aureus,  and  the  organisms  causing 

septicaemia  in  mice  and  rabbits 
(To  these  must  now  be  added  the  bacillus  enteritidis  sporogenes) 

Up  to  the  present,  however,  the  only  diseases  which  are 
certainly  caused  by  drinking  specifically-infected  water, 
and  the  micro-organisms  of  which  have  been  with  certainty 
discovered  in  such  waters,  are  cholera  and  typhoid  fever. 
Doubtless  further  research  will  add  to  this  short  list,  but 
as  yet  the  organisms  causing  malaria,  dysentery,  and  other 
diseases,  believed  to  be  produced  by  specific  microbes 
entering  the  system  with  the  drinking  water,  have  not  been 
with  certainty  identified  therein.  The  utmost,  therefore, 
that  can  be  expected  of  the  bacteriologist  is  that  he  should 
discover  and  identify  the  cholera  or  typhoid  bacillus,  should 
either  of  these  organisms  be  present  in  a  sample  of  water 
submitted  to  him  for  examination,  and  at  least  that  he 
should  be  able  to  discover  such  organisms  as  are  more  or 
less  characteristic  of  sewage.  The  multitude  of  other 
bacilli  present,  however,  renders  the  search  for  one  par- 
ticular organism  a  difficult  and  often  impossible  task ;  the 
search  has  been  likened  to  the  finding  of  a  needle  in  a  stack 
of  hay.  Whilst,  therefore,  the  absolute  identification  of 
the  specific  cause  of  cholera  or  typhoid  fever  establishes  its 
presence,  the  failure  to  isolate  it  is  no  proof  of  its  absence. 
As  a  matter  of  fact,  numerous  samples  of  water,  credited 
with  the  production  of  one  or  other  of  these  diseases  have 
been  examined  with  negative  results.  As  examples  may 
be  quoted  the  examinations  of  the  water  supplies  to 
Hamburg  and  Altona  during  the  cholera  epidemic,  and  the 
water  supplies  to  Worthing,  and  to  the  towns  in  the  Tees 
valleys,  during  the  outbreaks  of  typhoid  fever,  which 
recently  occurred  there.  Although  the  Elbe  was  known 
to  be  polluted  with  cholera  excreta,  the  comma  bacillus 
was  never  discovered  in  the  imperfectly-filtered  river  water, 


THE  INTERPRETATION  OF  WATER  ANALYSES     207 

to  the  use  of  which  Koch  and  others,  who  investigated  the 
outbreaks,  attributed  their  occurrence.  At  the  commence- 
ment of  the  second  serious  epidemic  of  typhoid  fever  at 
Worthing,  two  samples  of  the  water  were  submitted  to 
bacteriological  examination  by  Professor  Crookshank.  He 
found  that  they  contained  far  fewer  bacteria  than  the 
water  supplied  to  King's  College,  and  that  there  was  a 
marked  absence  of  liquefying  colonies.  "  There  was  no 
colony  of  typhoid  fever  bacilli,  and  no  bacillus  to  which 
suspicion  could  be  attached  of  producing  typhoid  fever." 
He  concluded,  from  the  results  of  his  bacteriological  exami- 
nation, "  that  both  samples  of  the  Worthing  water  rank 
as  very  pure  water."  Considering  that  during  the  con- 
struction of  additional  works  in  the  spring,  a  fissure  was 
opened  which  discharged  into  the  wells  a  large  volume  of 
water,  polluted  by  surface  drainage,  and  leakage  from 
defective  sewers,  and  that  this  mixture  of  well  and  surface 
water  thereafter  was  supplied  to  the  town,  and  was  the 
water  examined  by  Dr.  Crookshank,  it  is  not  surprising  • 
that  the  results  of  these  and  other  examinations  were 
considered  by  the  public  as  "  most  remarkable."  Chemical 
examinations  made  from  time  to  time  also  failed  to  detect 
any  pollution.  The  following  statements,  made  by  the 
Deputy  Mayor  of  Worthing  *  at  a  meeting  of  the  Town 
Council,  held  18th  July,  1893,  are  particularly  interesting, 
not  only  as  showing  how  little  reliance  can  be  placed  upon 
either  the  bacteriological  or  chemical  examination  of 
drinking  waters,  but  also  as  showing  the  disastrous  results 
which  may  follow  misplaced  confidence  in  these  results. 
The  Deputy  Mayor,  at  the  above  meeting,  after  speaking 
of  the  finding,  about  two  months  ago,  of  the  fissure  which 
gave  to  the  town  an  enormous  additional  yield  of  water, 
said  :  "  We  congratulated  ourselves  upon  that  fissure,  but 

*  From  Report  in  the  Sussex  Coast  Mercury,  22nd  July,  1893. 
Worthing  has  a  population  of  about  17,000,  and  during  the  year  1893 
nearly  1,500  cases  of  typhoid  fever  occurred. 


2oS  WATER  SUPPLIES 

I  think  there  is  no  doubt,  and  certainly  no  member 
of  the  Sanitary  Committee  has  any  doubt,  that  it  is  to  that 
very  fissure  the  whole  of  the  difficulty  we  are  sustaining, 
and  have  sustained,  is  entirely  due."  He  then  referred  to 
the  various  chemical  and  bacteriological  analyses  which 
had  been  made,  resulting  in  the  water  being  pronounced 
thoroughly  good  and  pure.  Notwithstanding  these  results 
the  Committee  cautioned  the  public  that  they  should  boil 
the  water,  and  the  boiling  went  on  until  the  first  outbreak 
practically  ceased.  "  We  were  hoping/'  he  said,  "  that  the 
difficulty  had  ceased,  and  that  we  were  to  have  no  more 
typhoid  among  us;  but,  unfortunately,  another  analysis 
was  made  by  Dr.  Crookshank,  the  water  being  -taken 
from  two  or  three  different  sources,  and  each  sample 
was  declared  to  be  good.  Perfectly  pure  were,  I  think,  the 
doctor's  words.  Well  now,  to  that,  I  am  afraid,  to  some 
extent,  we  may  attribute  the  cause  of  the  second  outbreak. 
It  was  stated  publicly,  with  the  best  intentions,  to  allay 
public  excitement  and  the  panic  which  was  prevailing, 
that  the  water  was  perfectly  pure,  because  we  had  the  best 
evidence  that  it  was  so;  and  I  have  no  doubt  that  the 
public,  who  do  not  like  the  trouble  of  boiling  every  drop 
of  water  they  drink,  ceased  the  boiling,  and  thus  the  second 
outbreak  came  upon  us,  and  is  still  going  on."  It  is  quite 
unnecessary  to  point  the  moral  of  this  plain  statement  of 
facts.  During  the  Tees  valley  epidemic,  also,  the  water 
was  repeatedly  examined  bacteriologically.  Although  an 
excessive  number  of  micro-organisms  was  found,  sufficient 
in  fact  to  justify  the  opinion  that  the  water  was  pol- 
luted, the  typhoid  bacillus  was  next  once  discovered. 

It  has  recently  been  asserted  that  the  so-called  typhoid 
bacillus  (Eberth's)  is  often  absent  from  typhoid  stools,  and 
that  the  bacillus  coli  communis,  which  is  invariably  found 
in  all  stools,  is  capable  under  certain  conditions  (probably 
by  growth  in  cesspools  and  sewers)  of  acquiring  pathogenic 
properties  in  man.  It  is  even,  by  many,  believed  that 


THE  INTERPRETATION  OF  WATER  ANALYSES      209 

this  is  either  a  degenerate  form  of  Eberth's  bacillus,  or 
that  it  is  capable  of  taking  on  the  same  properties,  and  of 
causing  the  same  disease — typhoid  fever.  Such  being  the 
case,  all  waters  fsecally  polluted  may  be  capable  of 
producing  this  disease  when  all  the  circumstances  are 
favourable,  and  therefore  they  must  be  looked  upon  with 
the  gravest  suspicion,  whatever  the  results  of  bacteriological 
or  chemical  analyses. 

All  surface  waters  contain  large  numbers  of  micro- 
organisms, but  freshly-drawn  deep-well  waters,  and  waters 
from  deep-seated  springs,  are  almost  sterile.  When  such 
pure  waters  are  kept  for  a  few  days,  however,  the  number 
of  micro-organisms  increases  enormously.  Professor  P. 
Frankland  says  that  such  a  water,  containing  only,  say, 
5  microbes  per  cubic  centimetre  when  freshly  drawn,  may, 
even  if  kept  in  a  sterile  flask  and  protected  from  aerial 
contamination,  contain,  after  a  few  days,  perhaps  500,000 
in  the  same  volume,  or,  in  other  words,  as  many  as  are 
found  in  slightly  diluted  sewage.  He  points  out,  however, 
that  whilst  in  sewage  the  numbers  only  gradually  diminish, 
in  these  pure  waters  "  after  the  rapid  increase  in  numbers 
follows  a  correspondingly  rapid  decline,  so  that  the  num- 
bers again  very  soon  fall  below  those  found  in  impurer 
surface  waters."  It  follows,  therefore,  that  the  purest 
water  which  has  been  kept  a  few  days  may  be  confounded 
with  a  water  from  the  filthiest  source,  and  that  even  if  the 
number  of  micro-organisms  found  in  a  water  is  to  be  taken 
as  a  criterion  of  its  purity  or  otherwise,  the  bacteriological 
examination  must  be  made  before  such  multiplication  can 
have  ensued.  In  freshly-drawn  deep-well  and  spring  waters 
there  should  be  few  or  no  bacteria ;  in  the  purest  mountain 
streams  and  lakes  there  should  not  be  more  than  a  few 
hundreds  in  a  cubic  centimetre  (15  drops).  In  ordinary 
river  waters  from  1,000  to  100,000  may  be  found  in  the 
same  volume,  whilst  in  sewage  there:  may  be  sieveral 
millions.  Rain,  hail,  snow,  and  ice  are  not  free  from 

14 


210  WATER  SUPPLIES 

bacteria,  though  usually  the  number  contained  therein  is 
small. 

Professor  Sheridan  Dele*pine,  in  a  recent  article  in 
the  Journal  of  State  Medicine,*  referring  to  the  various 
modes  of  examining  waters,  states  that,  in  his  opinion,  a 
bacteriological  examination  is  capable  of  giving  more  reli- 
able data  than  a  chemical  analysis,  especially  if  the  amount 
of  polluting  matter  is  small.  He  continues  :  "  Our  present 
position  with  regard  to  the  value  and  interpretation  of 
bacteriological  results  will  be  made  clear  by  a  few 
references  to  the  views  held  by  several  authorities. 

"  Koch  (1885)  says  that  the  number  of  micro-organisms 
in  water  is  of  the  greatest  importance,  as  it  indicates 
whether  or  not  the  water  is  contaminated  with  organic 
matter  undergoing  decomposition.  When  decomposing 
organic  matter,  which  always  contains  a  large  number  of 
bacteria,  gets  mixed  with  water,  this  water  becomes  rich 
in  micro-organisms.  Even  if  one  were  unable  to  discover 
any  pathogenic  germs  in  such  a  contaminated  water,  the 
fact  that  it  contains  decomposing  organic  products,  among 
which  pathogenic  bacteria  might  be  present,  is  enough  to 
render  this  water  suspicious. 

"  In  his  well-known  paper  on  water  nitration,  Koch,  in 
1893,  has  fixed  at  100  the  maximum  number  of  colonies 
that  may  be  allowed  to  be  present  in  1  c.c.  of  water  pro- 
perly filtered  through  sand.  Koch  admits  at  the  same  time 
that  a  few  of  the  bacteria  which  are  found  in  the  unfiltered 
water  may  pass  through  the  filter  and  be  found  in  the 
filtered  water.  There  does  not  seem  to  me,  therefore,  any 
very  good  reason  for  admitting  a  standard  for  unfiltered 
and  another  standard  for  filtered  water. 

"  Supposing  we  admit  a  numerical  standard,  we  must,  if 
we  follow  Koch,  regard  100  bacteria  as  the  highest  number 
compatible  with  purity  of  drinking  water. 

*  Vol.  VI.,  p.  145.  "Bacteriological  Survey  of  'Surface'  Water 
Supplies." 


THE  INTERPRETATION  OF  WATER  ANALYSES       211 

"  Miquel  (1891)  has  given  a  scale  of  purity,  which  I 
give  only  to  show  the  arbitrary  nature  of  the  classification 
of  waters  based  on  numbers  only.  It  must  be  remembered 
that  the  methods  used  by  Miquel  reveal  a  larger  number  of 
bacteria  than  the  usual  methods :  — 

Excessively  pure  water  .  0  to           10  per  1  cubic  centimetre. 

Very  pure  water     .         .  10  to         100         „                      ,, 

Pure  water      .         .         .  100  to      1,000         „                      „ 
Mediocre    (or    passable) 

water  ....  1,000  to    10,000 

Impure  water          .         .  10,000  to  100,000 

Very  impure  water          .  100,000  and  over           ,,                     ,, 

"  Crookshank  gives  in  1896  the  following  scale,  equally 
arbitrary  :  — 

Very  pure  water  may  con- 
tain up  to         .         .         .         100  bacteria  to  the  cubic  centimetre. 
Water  containing        .         .      1,000  bacteria,   or  more,   should   be 

filtered. 
Water  containing  more  than  100,000  bacteria  is  contaminated  with 

surface  water  or  sewage. 

"  Mace  (1897),  after  explaining  that  the  mere  number 
of  bacteria  must  be  taken  only  as  an  indication  and  not  as 
affording  an  absolute  criterion,  gives  the  following  scale 
of  purity  :  — 

Very  pure  water  .  0  to  10  bacteria  to  the  cubic  centimetre. 

Very  good  water  .  20  to  100                  „                  „ 

Good  water     .  .  100  to  200                  „ 
Passable  (mediocre) 

water  .         .  .  200  to  500 

Bad  water       .  .  500  to  1,000 

Very  bad  water  .  1,000  to  10,000  and  over  „  ,, 

"  Migula  (1890)  argues  that  the  mere  number  of  the 
colonies  affords  us  no  means  of  judging  of  the  fitness  of 
water  for  drinking  purposes,  but  that,  on  the  other  hand, 
a.  great  deal  depends  on  the  number  of  kinds  present. 


212  WATER  SUPPLIES 

"  Good  pure  spring  water  from  mountains  contains  only 
a  few  species ;  water  which  has  been  contaminated  by 
drainage  contains,  on  the  contrary,  an  exceedingly  great 
number  of  species. 

"  Migula  holds  that  there  should  never  be  more  than 
ten  different  species  of  bacteria  in  good  drinking  water. 
He  qualifies  this  statement  by  saying  that  a  water  con- 
taining fewer  species  may  have  to  be  condemned  on  account 
of  the  nature  of  the  bacteria,  whilst  sometimes  a  water 
containing  more  than  ten  kinds  may  be  considered  fit  for 
drinking  purposes. 

"  As  regards  the  number  of  colonies,  Migula  is  inclined 
to  admit  a  maximum  of  500,  i.e.,  the  limit  admitted 
by  most  observers.  For  a  time  bacteriologists  attached 
a  considerable  importance  to  the  presence  or  absence  of 
liquefying  bacteria,  but  I  think  that  as  there  are  several 
rapidly  liquefying  bacteria  often  present,  even  in  unpol- 
luted water,  it  is  necessary  to  distinguish  between  those 
liquefying  bacteria  which  are  associated  with  pollution 
and  those  which  are  not,  if  the  presence  of  liquefying 
bacteria  is  to  be  used  as  a  criterion  at  all. 

"  Meade-Bolton,  jLustig,  G.  Roux,  all  well  known  in 
connection  with  the  bacteriological  examination  of  water, 
have  expressed  views  similar  to  but  less  categorical  than 
those  just  quoted. 

"  I  need  not  say  more  to  show  that  there  is,  as  yet,  no 
consensus  of  opinion  among  bacteriologists  with  regard  to 
the  interpretation  of  the  results  of  water  analysis.  There 
is,  however,  a  general  tendency  to  admit  that  much  judg- 
ment has  to  be  used  in  interpreting  these  results. 

"  There  is  no  difficulty  with  regard  to  very  bad  waters. 
Those  who  propound  numerical  standards  all  agree  that  a 
water  containing  1,000  germs  is  not  good.  This  in  itself  is 
already  a  very  important  point  gained,  for  in  many  sus- 
picious or  bad  waters  which  might  chemically  appear  good, 
the  presence  of  organic  impurities  can  easily  be  detected 


THE  INTERPRETATION  OF  WATER  ANALYSES      213 

in  this  way.  But  when  we  have  to  deal  with  waters 
containing  less  than  1,000  bacteria  to  the  cubic  centimetre, 
there  is  a  considerable  divergence  in  the  views  expressed  by 
various  writers." 

Professor  Dele'pine  adopts  a  comparative  method  in  all 
his  investigations,  and  says  that  it  has,  so  far,  yielded  him 
results  which  appear  free  from  ambiguity  when  applied  to 
the  investigation  of  surface  and  subsoil  waters.  He  selects 
waters  from  sources  which  by  examination  are  shown  to  be 
free  from  the  possibility  of  pollution,  and  taking  these  for 
his  standards  compares  therewith  other  waters  from  the 
same  subsoil,  or  from  other  portions  of  the  same  collecting 
surface. 

In  the  Report  of  the  Medical  Officer  to  the  Local  Govern- 
ment Board  (1897-8)  there  are  interesting  reports  by  Drs. 
Klein  and  Houston,  showing  that  contaminating  matters 
in  waters  which,  from  the  chemist's  point  of  view,  would 
be  classed  as  "  of  high  degree  of  organic  purity  "  can  be 
detected  by  bacteriological  examination,  the  bacillus  coli 
and  bacillus  enteritidis  in  a  water  being  taken  as  evidence 
of  its  previous  sewage  contamination.  These  results  I  have 
been  able  to  verify,  but  occasions  have  arisen  when  one  or 
other  of  these  organisms  have  been  found  in  a  water  which, 
from  an  examination  of  the  source,  I  could  vouch  for  being 
"  safe."  I  am  not  certain,  as  yet,  however,  that  I  have  ever 
met  with  a  "  safe  "  water  which  contained  both  these 
organisms. 

In  a  more  recent  report  (L.G.B.  Report  1898-9)  these 
observers  state,  as  the  results  of  the  investigations  recorded, 
"  that  not  only  is  bacteriology  capable  of  detecting,  in  a 
water  .  .  .  microbes  characteristic  of  sewage,  but  is  capable 
also  of  detecting  these  bacteria  when  the  degree  of  sewage 
pollution  of  the  water  is  from  ten  to  one  hundred  times 
less  than  that  in  which  the  organic  matter  contributed  by 
the  sewage  to  the  water  has  failed  to  get  recognition  by 
the  methods  commonly  in  use  by  the  chemist."  n 


2i4  WATER-SUPPLIES 

In  another  article  in  the  same  report  by  Dr.  Houston, 
it  is  asserted  that  the  presence  of  streptococci  in  any 
number  in  a  water  "  is  positive  evidence  of  a  sort  to  go  far 
to  justify  the  bacteriologist  in  condemning  a  sample  of 
water  as  unfit  for  domestic  use/'  since  such  organisms 
appear  only  to  be  found  in  water  recently  polluted  by 
sewage.  I  have,  however,  found  streptococci  in  "  new " 
wells  free  from  the  possibility  of  pollution. 

Koch  would  regard  even  filtered  river  water  containing 
over  100  micro-organisms  in  a  cubic  centimetre  as  open  to 
suspicion;  but,  as  we  have  just  seen,  he  does  not  regard 
such  water,  if  once  polluted,  as  absolutely  safe,  however 
careful  and  (thorough  the  filtration.  The  Royal  Com- 
missioners on  Metropolitan  Water  Supply  do  not  entirely 
concur  with  this  conclusion.  They  point  out  that  the 
typhoid  bacillus  is,  so  far  as  is  known,  only  found  in  human 
excrement,  and  that  it  has  not  yet  been  found  to  retain 
its  vitality  when  in  faecal  matter  for  more  than  15  days; 
that  in  all  ordinary  waters  there  exist  organisms  which 
11  undoubtedly  exert  an  influence  in  diminishing  the 
vitality  of  the  typhoid  bacillus;  that  exposure  to  direct 
sunlight  destroys  these  bacteria ;  that  they  have  a  tendency 
to  subside  more  or  less  rapidly  in  all  slowly-moving  waters, 
and  to  be  carried  down  with  other  matters  held  in  suspen- 
sion; and  that  there  are  strong  grounds  for  believing  that 
small  doses  either  of  cholera  or  of  typhoid  poison  may  be 
swallowed  with  impunity.  Such  being  the  case,  they  fall 
back  upon  the  "  evidence  of  experience/'  and  whilst  acknow- 
ledging that  the  various  water  supplies  to  London  are 
contaminated  with  sewage,  which  may,  and  often  does, 
contain  the  specific  poison  of  typhoid  fever,  and  may 
contain  the  bacillus  of  Asiatic  cholera,  they  "  state  without 
hesitation,  that,  'as  regards  the  diseases  in  question,  which 
are  the  only  ones  known  to  be  disseminated  by  water, 
there  is  no  evidence  that  the  water  supplied  to  the  con- 
sumers in  ;Londo<n  by  the  companies  is  not  perfectly 


THE  INTERPRETATION  OF  WATER  ANALYSES      215 

wholesome."  In  other  words,  these  polluted  river  waters, 
which  have  undergone  a  nitration  as  perfect  as  that  re- 
quired by  Koch  (since  the  freshly  filtered  London  water 
now,  1900,  usually  contains  less  than  one  hundred  micro- 
organisms in  the -cubic  centimetre),  are  perfectly  safe  and 
wholesome. 

In  reputedly  good  waters  it  has  been  observed  that  the 
micro-organisms  present  capable  of  liquefying  gelatine  by 
their  growth  are  few  in  number,  whilst  in  sewage-polluted 
waters  they  abound;  but  this  fact  is  of  little  value,  since 
it  only  enables  somewhat  gross  pollution  to  be  detected, 
and  most  of  these  liquefying  organisms  are  perfectly  harm- 
less. The  attempt  to  set  up  a  standard  of  purity  based 
upon  the  number  of  microorganisms  in  a  given  quantity  is 
as  illogical  as  the  old  chemical  standards.  Both  depend 
upon  quantity,  whilst  the  real  point  at  issue  is  the  quality. 
Bacteriology,  like  chemistry,  may  tell  us  something  of 
hazard  and  impurity,  but  the  latter  certainly  cannot  be 
depended  upon  to  determine  whether  a  water  is  dangerous 
to  health.  To  condemn  one  water  because  it  yields  a  little 
more  albuminoid  ammonia  than  another,  or  because  it 
contains  a  few  more  organisms  than  another,  when  we 
know  nothing  of  the  nature  of  the  substance  yielding  the 
ammonia,  and  nothing  of  the  character  of  the  organisms, 
is  obviously  so  illogical  as  to  be  absurd,  and  yet  this  is 
what  is  almost  invariably  done.  Bacteriological,  micro- 
scopical, and  chemical  examinations  must  always  be 
associated  with  a  thorough  investigation  of  the  source  of 
the  water,  to  ascertain  the  possibility  of  contamination, 
continuous  or  intermittent.  Then,  and  then  only,  if 
everything  be  satisfactory,  we  may  be  justified  in  speaking 
of  safety  and  of  freedom  from  risk;  but  where  either  the 
bacteriological,  microscopical,  or  chemical  examination  is 
unsatisfactory,  the  inquiry  into  the  history  of  the  water 
must  be  most  careful  and  complete,  and  a  guardedly- 
expressed  opinion  given  only  after  a  full  consideration  of 


216  WATER  SUPPLIES 

the  bearing  of  the  one  upon  the  other.  The  views  here 
advocated  are  now  generally  accepted  on  the  Continent. 
Max  Griiber,  of  Vienna,  lays  the  greatest  stress  in  water 
examination  upon  the  all-importance  of  personal  inspection 
of  the  source  of  supply.  He  even  believes  that  in  ordinary 
cases  the  bacteriological  examination  can  be  dispensed 
with.  Fltigge  considers  that  the  inspection  of  the  source 
and  the  arrangements  of  a  water  supply  carried  out  with 
the  unaided  senses  is  the  most  desirable  method,  and 
seldom  needs  to  be  supplemented  by  chemico-bacteriological 
or  microscopical  investigations.  The  possibility  of  acci- 
dental pollution  is  a  point  too  often  overlooked ;  yet  it  is 
to  such  accidental  pollution  that  outbreaks  of  disease  are 
most  frequently  attributed,  and  of  this  the  examination  of 
samples  of  water,  prior  to  the  occurrence  of  the  contamina- 
tion, may  tell  us  little  or  nothing.  In  January,  1897,  a 
very  striking  illustration  of  this  fact  came  under  my 
notice.*  An  outbreak  of  typhoid  fever  occurred  in  a 
town  in  Essex,  limited  to  children  who  had  used  water 
from  a  certain  drinking  fountain.  The  water  had  been 
submitted  to  a  chemist,  who  certified  that  it  was  all  that 
could  be  desired  and  that  no  suspicion  could  be  attached 
to  it.  I  was  consulted,  and  upon  inquiry  found  that  the 
water  had  recently  been  observed  to  become  turbid  after 
rain.  At  my  request  the  water  was  traced  to  its  source. 
It  was  found  to  be  conveyed  in  unjointed  earthenware 
pipes  from  a  spring  to  a  tank  supplying  the  fountain  near 
the  foot  of  the  hill.  At  one  point  the  pipes  were  crossed 
by  a  sewer,  the  top  of  which  had  by  some  means  been 
crushed  in.  During  heavy  rains  there  was  an  overflow 
from  the  sewer  into  the  water  pipes  beneath.  A  little 
distance  above,,  the  sewer  received  the  drainage  from  a 
small  isolation  hospital  in  which,  a  few  weeks  prior  to  the 
outbreak,  there  had  been  a  patient  suffering  from  enteric 

*  Vide  Journal  of  State  Medicine,  Vol.  V.,  p.  178. 


THE  INTERPRETATION  OF  WATER  ANALYSES      217 

fever.  In  this  case  the  chemist  who  examined  the  water 
in  the  first  instance  said  emphatically  that  the  water  could 
not  possibly  be  the  cause  of  the  epidemic,  as  his  analysis 
showed  it  to  be  of  excellent  quality.  My  analysis  of  a 
sample,  taken  at  a  later  date  and  after  a  heavy  rain,  gave 
very  different  results  and  proved  serious  pollution. 

The  danger  of  such  intermittent  pollution  can  rarely  be 
discovered  by  analysis,  since  a  source  yielding  under  normal 
conditions  a  water  of  great  chemical  and  bacterial  purity 
may  be  more  liable  to  occasional  fouling  than  a  source 
yielding  water  containing  excessive  quantities  of  chlorides 
and  nitrate®,  or  even  of  unoxidised  organic  matter. 


CHAPTER  XI. 

THE  POLLUTION  OF  DRINKING  WATER. 

IN  the  preceding  chapters  many  illustrations  will  be  found 
of  the  ways  in  which  water  may  become  polluted ;  and  in 
the  succeeding  chapters  frequent  reference  will  have  to  be 
made  to  the  subject;  yet  it  appears  advisable  to  consider 
it  here  somewhat  systematically,  since  it  forms  a  natural 
supplement  to  the  two  preceding  sections.  From  what  has 
been  already  said  it  is  evident  that  by  far  the  most 
dangerous  polluting  matters  which  can  gain  access  to  a 
drinking  water  are  the  solid  and  liquid  waste  products 
cast  out  of  the  human  system  and  usually  deposited  in 
cesspits,  cesspools,  drains,  and  sewers.  There  is  a  wide- 
spread and  very  erroneous  impression  that  in  districts 
without  water-closets  the  drainage,  consisting  merely  of 
slop  water,  is  practically  innocuous,  and  that  it  may  be 
disposed  of  in  ways  not  admissible  with  ordinary  sewage. 
Chemically  and  bacteriologically,  it  is  almost  impossible  to 
distinguish  between  the  sewage  of  towns  in  which  water- 
closets  are  in  general  use,  and  of  towns  in  which  other 
forms  of  excrement  collection  and  disposal  are  adopted. 
In  the  drainage  from  the  former  we  have  all  the  chamber 
slops,  the  water  in  which  soiled  bed-linen,  clothing,  etc., 
have  been  washed;  and  both  these  are  not  only  excessively 
foul,  but  may  also  be  specifically  polluted.  Both  kinds  of 
sewage,  therefore,  must  always  be  dangerous;  and  every 
effort  should  be  made  to  prevent  their  gaining  access  to 
any  source  of  water  supply. 

(218) 


THE  POLLUTION  OF  DRINKING  WATER  219 

Pollution  of  Water  at  its  Source. 

(a)  Rain  and  Rain  Water.— Rain  water,  if  collected  with 
ordinary  care,  is  never  likely  to  be  polluted  with  human 
excrement.     It   frequently   contains   the   ordure   of   birds, 
soot,    dust,    and    decaying   vegetable   matters,    which   have 
accumulated  during  the  dry  weather  on  the  collecting  area, 
and  all  of  which  are  more  or  less  objectionable ;  but  I  know 
of  no  instance  in  which   the  use  of  such  rain  water  has 
caused    disease     (vide    Chapter    II.).     These     constituents 
usually   render    the    water    so    unsightly    and    unpalatable 
that  no  one  will  use  it  until  after  it  has  been  filtered  or 
boiled ;    and    this    may    account    for    the    absence    of    any 
deleterious  effects.     Such  rain  water,  when  kept,  appears  to 
undergo  some  process  of  fermentation  and  self-purification, 
which  renders  it  again  bright  and  fairly  palatable.     When 
collected  by  aid  of  a  "  separator,"  so  as  to  prevent  the  first 
washings   of   the   roof   or   other   collecting   surface   passing 
into  the  reservoir  or  tank,  and  when  properly  stored,  the 
rain  furnishes  probably  the  safest  of  all  waters  for  drinking 
purposes. 

(b)  Surface   and   River    Waters.- — Water    collected    from 
uninhabited  moorland  or  mountainous  districts  may  con- 
tain   vegetable    matter,    but    will    be    free    from    animal 
pollution.     If  from  cultivated  land,  manurial  matters,  more 
or  less  changed  by  oxidation,  will  gain  access  to  the  water. 
As  human  excrement  is  constantly  employed  as  manure, 
the  pollution  may  be  of  a  dangerous  character.     In  such 
districts  also  there  must  be  human  habitations,  farmyards, 
etc. ;  and  unless  special  precautions  are  taken,  the  drainage 
from  these  will  contaminate  the  water.     Cesspits  and  cess- 
pools are  frequently  so  defectively  constructed  as  to  permit 
of  the  contents  being  washed  out  by  heavy  rains;   or  they 
may  overflow  into  ditches,  and  the  filth  be  carried  into  the 
nearest  watercourse.     During  dry  seasons  such  streams  may 
receive  but  little  polluting  matter,  whilst  in  seasons  of  flood 


220  WATER  SUPPLIES 

the  accumulated  filth  of  months  may  be  carried  into  them. 
In  too  many  instances  the  whole  of  the  sewage  of  towns  ip 
discharged  bodily  into  rivers  which  are  used  a  few  miles 
lower  down  as  the  water  supply  to  other  towns  and  villages. 
No  doubt  in  the  course  of  transit  from  point  to  point  much 
of  the  solid  matter  is  deposited  on  the  sides  and  bottom  of 
the  river,  and  some  of  the  dissolved  filth  is  oxidised  or 
otherwise  destroyed ;  but  it  is  open  to  question  whether 
any  river  in  this  country  is  sufficiently  long  for  this  process 
of  self-purification  to  be  complete,  and  for  the  water  to 
become  absolutely  free  from  danger.  With  every  flood  the 
deposited  filth  is  disturbed  and  carried  downwards ;  and 
unless  due  provision  has  been  .made  for  tiding  over  these 
periods  without  having  to  abstract  the  turbid  water, 
seriously-polluted  water  may  have  to  be  used,  and  if  the 
filtration  be  not  perfect,  serious  consequences  may  ensue. 
Many  outbreaks  of  typhoid  fever  have  been  attributed  to 
the  use  of  such  waters.  For  long  periods  the  consumption 
of  the  water  may  have  produced  no  injurious  effects;  but 
an  exceptional  flood  or  the  failure  of  a  filter  bed  at  a 
critical  period  may  result  in  a  serious  outbreak  of  disease. 
Examples  of  epidemics  so  produced  have  already  been 
referred  to.  No  doubt  the  danger  arising  from  the  intro- 
duction of  sewage  into  a  stream  supplying  drinking  water 
varies  with  the  proportion  of  sewage  to  the  volume  of  water 
into  which  it  is  discharged ;  but,  however  small  this 
proportion,  it  cannot  be  said  that  the  degree  of  dilution  is 
sufficient  to  render  the  water  entirely  safe.  When  sewage 
has  been  purified  by  chemical  treatment  or  by  filtration 
through  land,  doubtless  the  danger  is  reduced  to  a 
minimum,  but  there  is  always  the  risk  of  imperfectly- 
purified  sewage  being  carried  into  the  stream.  Where 
the  sewage  is  treated  by  one  of  the  recent  bacteriological 
processes,  a  still  greater  degree  of  purification  is  attained. 
If  the  process  be  suitably  chosen,  and  effectively  carried 
out,  putrefaction  of  the  effluent  is  prevented,  and  the 


THE  POLLUTION  OF  DRINKING  WATER  221 

greater  portion  of  the  nitrogenous  matter  is  converted  into 
nitrates.  Unfortunately,  however,  there  is  no  evidence 
that  specific  pathogenic  organisms  are  removed  by  such  a 
process.  That  the  effluent  from  a  sewage  farm  may  pollute 
a  drinking  water  in  such  a  way  as  to  cause  disease  seems 
probable  from  the  report  on  the  outbreak  of  typhoid  fever 
at  Beverley  already  mentioned.  It  is  true  that  in  this 
case  the  water  contaminated  was  derived  from  a  well ;  but 
had  the  effluent  found  its  way  into  a  stream  used  as  a 
water  supply,  it  is  not  improbable  that  the  result  would 
have  been  the  same  (vide  Chapter  XII.,  on  the  "  Self- 
purification  of  River&"). 

(c)  Subsoil  Water. — In  thinly-populated  districts  the 
subsoil  water  may  be  absolutely  free  from  any  trace  of 
sewage  contamination.  In  populous  districts,  on  the  other 
hand,  a  considerable  amount  of  sewage  must  gain  access  to 
the  subsoil.  Fortunately,  however,  the  "  living "  earth 
possesses  such  purifying  properties  that  the  filth  may  be 
rendered  perfectly  powerless  for  evil.  In  fact,  Koch  has 
given  it  as  his  opinion  that  "  the  subsoil  water  gives  us 
absolute  security  with  respect  to  the  danger  of  infection, 
and  it  should,  therefore,  if  it  can  only  be  obtained  in 
sufficient  quantity,  and  if  it  is  not  objected  to  on  account 
of  chemical  characteristics,  e.g.,  too  great  hardness,  or  too 
great  an  admixture  of  chloride,  be  preferred  under  all 
circumstances  to  surface  water.  I  indeed  hold  it  even  to 
be  desirable,  and  in  some  cases  even  necessary,  that  works 
already  constructed  to  filter  river  water  should  be  so 
changed  as  to  be  used  for  obtaining  subsoil  water."  As 
most  subsoil  waters  have  received  an  admixture  of  sewage, 
how  is  it  that  such  a  careful  observer  as  Koch  can  regard 
it  as  under  all  circumstances  preferable  to  surface  water? 
The  fertility  of  soil  depends  upon  the  presence  of  organic 
matter,  vegetable  or  animal,  undergoing  decay.  This 
decay  is  almost  entirely  due  to  the  action  of  micro- 
organisms, which  produce  nitric  and  carbonic  acids,  without 


222  WATER  SUPPLIES 

the  former  of  which  the  soil  would  be  practically  barren. 
The  decomposition  of  organic  matter  appears  to  take  place 
in  three  stages.  First,  ammonia  is  produced,  and  this 
probably  by  the  action  of  several  species  of  bacteria;  next, 
the  ammonia  is  converted  into  nitrous  acid  by  an  organism 
discovered  simultaneously  in  1890  by  Frankland  and 
Winogradsky;  finally,  another  organism  has  been  proved 
by  Warrington  and  Winogradsky  to  be  the  cause  of  the 
conversion  of  the  nitrous  into  nitric  acid.  In  rainless 
districts  nitrates  accumulate  upon  the  surface,  immense 
deposits  being  found  in  Chili,  Peru,  and  various  parts  of 
India.  In  other  regions  the  nitrates  so  formed  are  dis- 
solved by  the  rain  and  carried  to  the  roots  of  plants,  and 
serve  for  their  nourishment.  The  proportion  not  so  utilised 
by  plants  as  food  passes  into  the  subsoil  water.  All  the 
organisms  above  referred  to  are  found  most  abundantly  in 
the  first  few  inches  of  soil,  the  numbers  decreasing  rapidly 
with  the  depth,  until  at  a  few  feet  from  the  surface  they 
are  no  longer  to  be  detected.  Where  the  surface  is  covered 
with  vegetation,  the  decomposition  of  dead  organic  matters 
is  so  complete,  and  the  amount  of  nitrate  extracted  so 
large,  that  no  undecomposed  organic  matter  and  little  of 
the  products  of  its  decay  reaches  the  subsoil  water.  More- 
over the  undisturbed  soil  constitutes  one  of  the  most 
perfect  of  filters;  hence  subsoil  water,  if  properly  collected, 
is  one  of  the  purest  of  waters,  providing  the  mineral 
ingredients  of  the  subsoil  are  not  too  soluble,  or  are  not  of 
an  otherwise  objectionable  character.  In  towns  and  villages 
where  there  are  aggregations  of  houses,  or  even  in  the 
proximity  to  single  cottages,  the  surface  soil  may  be  so 
denuded  of  vegetation  that  this  process  of  decomposition 
may  not  be  complete,  and  unchanged  or  only  partially 
-changed  filth  may  be  washed  through  into  the  ground 
water.  Where  the  filth  escapes  from  defective  drains, 
cesspools,  and  cesspits,  this  is  still  more  likely  to  be  the 
case;  hence  water  obtained  from  wells  in  proximity  to 


THE  POLLUTION  OF  DRINKING   WATER  223 

such  defective  sanitary  arrangements  must  be  polluted. 
In  towns  and  villages,  especially  where  such  defects  are 
common,  the  whole  of  the  subsoil  water  over  a  large  area 
may  be  contaminated.  Doubtless  even  here  the  filtering 
powers  of  the  earth  are  most  marked,  otherwise  outbreaks 
of  disease  would  be  much  more  frequent  amongst  com- 
munities using  such  water;  but  the  records  of  every 
medical  officer  of  health  prove  that  this  nitration  cannot 
always  be  depended  upon  to  remove  the  germs  of  disease. 
A  heavy  rainfall,  either  by  carrying  the  filth  through 
with  unusual  rapidity,  or  by  causing  the  ground  water  to 
rise  into  the  more  polluted  soil  above,  may  carry  these 
organisms  into  the  wells,  and  so  produce  an  epidemic. 
Where  wells  are  improperly  constructed  and  allow  of  water 
entering  at  or  near  the  surface,  the  danger  is  greatly 
accentuated.  Where  they  are  open  at  the  ground  surface, 
or  where  'the  covering  is  defective,  heavy  rains  may  wash 
the  filth  directly  into  the  water.  The  great  difficulty 
experienced  in  constructing  wells  so  as  to  exclude  impure 
surface  water  leads  Koch  to  conclude  that  "  Wells,  con- 
structed no  matter  how,  should  not  be  tolerated  in  future  " 
(vide  Chapter  IV.).  Koch's  remarks,  therefore,  do  not 
apply  to  ground  water  as  derived  from  wells  of  any  kind. 
It  must  also  be  remembered  that  where  the  subsoil  is  full 
of  fissures,  impurities  may  be  carried  along  such  channels 
for  considerable  distances  and  contaminate  the  drinking 
water  at  a  point  far  from  where  the  polluting  matter  enters 
the  ground.  Thus  the  epidemic  of  typhoid  fever  at  New 
Herrington  was  proved  to  be  due  to  the  drainage  from  a 
farm  three-quarters  of  a  mile  away  from  the  well,  the 
channel  of  intercommunication  being  undoubtedly  the 
fissures  in  the  rock  forming  the  subsoil. 

The  natural  level  of  water  in  a  shallow  well  is  that  of  the 
plane  of  saturation  of  the  subsoil,  A,  C  (Fig.  13).  When  the 
level  of  the  water  in  the  well  is  lowered  by  pumping,  an 
area  of  ground  around  is  drained,  the  extent  of  this  area 


224 


WATER  SUPPLIES 


depending  upon  the  porosity  of  the  soil  and  the  depth  to 
which  the  water  is  abstracted.  The  ground  drained  has 
the  form  of  an  inverted  cone,  with  a  rapidly-increasing 
gradient  towards  the  well,  E.  The  drainage  area  has 
been  found  by  experiment  to  have  a  radius  ranging 
from  15  to  160  times  that  of  the  depression  due  to 
pumping;  hence  polluting  matters  gaining  access  to  the 
subsoil  within  this  area  will  flow  into  the  well.  The  extent 


FIG.  13. 


of  the  drainage  area  varies  with  the  porosity  of  the  soil; 
where  the  soil  is  dense  and  but  slightly  pervious  the  area 
may  not  exceed  15  times  the  depth  of  the  water  in  the  well 
when  at  its  highest  level,  whereas  where  the  subsoil  is 
exceedingly  porous  the  area  may  be  160  times  this  depth. 
As  in  most  cases  the  subsoil  water  is  travelling  in  a  definite 
direction,  if  the  point  of  pollution,  B,  be  where  the  plane 
of  saturation  is  higher  than  that  around  the  'well,  and  the 


THE  POLLUTION  OF  DRINKING  WATER  225 

latter  is  in  the  line  of  flow  of  the  subsoil  water  from  where 
the  pollution  enters,  it  is  tolerably  certain  to  gain  access 
to  the  well,  either  continuously  or  occasionally,  when  the 
level  of  the  ground  water  rises  above  a  certain  height.  If 
the  sewage  or  other  polluting  matters  enter  the  subsoil  at 
the  other  side  of  the  well,  the  risk  of  contamination  is 
greatly  diminished.  Hence,  in  districts  where  the  ground 
water  is  polluted  locally,  the  position  of  the  well  is  of 
considerable  importance. 

The  prevalence  of  malarial  diseases,  enteric  fever,  and 
cholera  is  believed  by  many  sanitarians  to  be  influenced 
largely  by  the  rise  and  fall  of  the  ground  water.  Fre- 
quently, in  India,  outbreaks  of  malaria  liave  followed  a 
rapid  rise  in  the  ground  water,  due  to  heavy  rainfalls,  and 
the  epidemics  may  have  been  due  to  the  contamination 
of  the  wells  by  the  filth  carried  down  by  the  rain. 
Pettenkofer,  at  Munich,  found  that  enteric  fever  was  most 
fatal  when  the  subsoil  water  was  lowest,  and  especially 
when  the  fall  had  been  rapid  and  from  an  unusual 
height.  Fodor,  at  Buda-Pesth,  found  exactly  the  opposite 
condition  to  obtain,  the  enteric  fever  mortality  rising  and 
falling  with  the  ground  water ;  and  this  connection  between 
the  height  of  the  subsoil  water  and  the  prevalence  of 
enteric  fever  has  been  observed  from  time  to  time  in  this 
country.  Where  this  has  occurred,  the  explanation  which 
suggests  itself  is,  that  the  water  had  become  more  and  more 
polluted  with  the  rise  in  level,  and  this  is  the  generally- 
accepted  opinion  in  this  country;  but  there  are  many 
eminent  observers  both  here  and  on  the  continent  who  do 
not  accept  this  explanation.  Pettenkofer  also  regards 
cholera  as  a  disease,  the  spread  of  which  is  largely  in- 
fluenced by  the  movements  of  the  subsoil  water.  Even  if 
such  is  the  case,  which  is  by  no  means  generally  admitted, 
it  may  be  that  the  effect  is  due  rather  to  the  varying 
extent  to  which  the  water  becomes  polluted,  rather  than 
to  the  fouling  of  the  ground  air  by  the  decomposition  of 

'5 


226  WATER  SUPPLIES 

the    organic    matter    and    the    active    growth    of    specific 
organisms  in  the  damp  soil  left  by  the  falling  ground-water. 
Baldwin  Latham  has  asserted  that  at  Croydon,  which  is 
supplied  with   water  from   springs  in  the  chalk,   measles, 
whooping-cough,     and     diphtheria     were     more    prevalent 
during  wet  seasons,  when  the  ground-water  level  was  high, 
and  that  typhoid  fever  and  small-pox  were  liable  to  become 
epidemic  when  heavy  rains  followed  a  prolonged  drought. 
Springs  fed  by  subsoil  water  will   be   affected  in  quality 
in  the  same  way  as  the  water  in  wells,  but  only  rarely  to 
the  same  extent.     Such  springs  usually  drain  considerable 
areas,  and  therefore,  unless  the  pollution  arises  near  the 
source  of  the  spring,  the  dilution  will  be  great,  and  during 
the  period  which  must  elapse  between  the  impurity  enter- 
ing the  ground  and  its  reaching  the  outlet,  time  will  have 
been    allowed   for    a   more   or   less    complete    oxidation    of 
the    organic    matter    in    the    pores    of    the    soil,    and    for 
a    more    or    less    complete    filtration    to    have    occurred. 
In  rural  districts  springs  are  frequently  fouled  by  cattle, 
and  by  the  rainfall,  if  heavy,  washing  filth  into  the  dipping 
places,  since  the  springs  are  not  properly  protected.     Land 
springs,  fed  by  thin  beds  of  sand,  or  gravel,  or  light  porous 
soil    of    any    kind,    are    especially    liable    to    be    seriously 
affected  by  manure  spread  upon  the  surface  of  the  ground, 
and  if  this  manure  contain  human  excrement  the  danger 
is  greatly  enhanced.     In  a  recent  outbreak  of  typhoid  fever 
which  I  investigated,  and  which  affected  a  small  group  of 
cottages,  I  found  that  the  excreta  from  a  mild  case  of  this 
fever  had  been  discharged  into  a  defective  privy  cesspit 
sunk  in  the  porous  soil  within  a  few  feet  of  the  land  spring 
which  supplied  the  cottages. 

When  slop  water,  the  contents  of  earth-closets,  etc.,  are 
properly  disposed  of  by  spreading  upon  a  sufficiently  large 
area  of  garden  or  other  cultivated  ground,  the  danger  of 
specific  pollution  of  the  ground  water  is  reduced  to  a 
minimum.  Where  the  sewage  escapes  from  defective  drains 


THE  POLLUTION  OF  DRINKING  WATER  227 

at  some  depth  from  the  surface,  and  excremental  filth 
oozes  through  the  sides  of  cesspools  and  cesspits  sunk  in 
the  ground,  the  danger  of  pollution  is  considerable,  and 
increases  with  the  proximity  of  these  defects  to  the  point 
from  which  the  subsoil  water  is  abstracted.  The  model 
bye-laws  of  the  Local  Government  Board  require  not  only 
that  the  drains,  cesspits,  and  cesspools  shall  be  so  con- 
structed as  to  prevent  any  such  leakage,  but  also  that  the 
two  latter  shall  not  be  constructed  within  a  certain  distance 
from  "  any  well,  spring,  or  stream  of  water  used,  or  likely 
to  'be  used,  by  man  for  drinking  or  domestic  purposes,  or 
for  manufacturing  drinks  for  the  use  of  man/'  Under 
ordinary  circumstances  the  distance  from  a  privy  should 
be  not  less  than  40  to  50  feet.  Cesspools  being  still 
more  dangerous,  the  minimum  distance  from  a  well  should 
not  be  less  than  60  to  80  feet.  Since  dust  and  debris,  when 
being  cast  into  ashpits,  may  be  blown  about,  and  so  gain 
access  to  a  well  or  stream  supplying  drinking  water,  no 
ashpit  should  be  less  than  30  to  40  feet  from  the  water 
supply.  The  proper  paving  of  yards,  of  pig-styes,  stables 
and  cowsheds,  of  slaughter  houses,  of  business  premises, 
especially  where  offensive  trades  are  carried  on,  efficient 
drainage  and  sewerage,  and  a  proper  system  of  sewage 
disposal,  are  all  necessary,  not  only  for  preventing  the 
pollution  of  the  ground  water,  but  also  of  the  ground  air, 
the  condition  of  the  latter  being  probably  as  important  a 
factor  in  determining  the  salubrity  or  otherwise  of  a 
locality  as  the  condition  of  the  former.  The  burial  of  the 
carcasses  of  animals  near  a  well  may  cause  pollution  of  the 
water,  and  it  is  believed  that  anthrax  may  be  spread 
amongst  cattle  by  the  use  of  water  contaminated  by  the 
decomposing  bodies  of  other  animals  which  have  died  from 
that  disease.  The  proximity  of  a  graveyard  to  a  source 
of  water  supply  is  certainly  undesirable ;  but  if  the 
direction  of  flow  of  the  ground  water  be  from  the  well 
towards  the  graveyard,  danger  will  only  arise  when,  by 


228  WATER  SUPPLIES 

pumping,  some  of  tlie  graves  are  brought  within  the 
drainage  area.  If  the  distance  from  the  graves  to  the  well 
be  sufficient  to  exclude  the  former  from  the  drainage  area 
of  the  latter,  however  heavy  and  continuous  the  pumping 
required  for  the  supply  of  water,  there  will  be  little  or  no 
danger  of  contamination  from  this  source.  If,  on  the  other 
hand,  the  flow  of  water  be  from  the  graveyard  towards  the 
well,  or  the  well  be  within  the  drainage  area  above 
described,  the  supply  will  almost  certainly  be  contaminated. 
Such  waters,  and  waters  from  the  neighbourhood  of  battle- 
fields, have  frequently  given  rise  to  dysenteric  diarrhoea 
amongst  the  populations  consuming  them. 

It  is  well  known  that  the  earth  around  gas  mains 
acquires  an  offensive  and  peculiar  odour.  Where  the  mains 
are  defective  this  smell  is  most  marked,  and  perceptible  at 
a  great  distance  from  the  pipes.  It  may  even  reach  the 
ground  water  and  taint  the  wells.  In  1884  the  wells  in  the 
Clarence  Victualling  Yard  at  Portsmouth  had  to  be  closed 
on  account  of  the  impregnation  of  the  water  with  coal  gas 
which  had  escaped  from  the  leaky  mains  traversing  the 
yard.  "  In  Berlin  in  1864,  out  of  940  public  wells,  39  were 
contaminated  by  admixture  with  coal  gas  "  (Parkes). 

(d)  Deep-Well  Water. — The  pollution  of  deep-well  water 
very  frequently  arises  from  defects  in  the  construction  of 
the  well.  If  the  sides  are  perfectly  impervious  and  the 
top  properly  protected,  the  access  of  surface  water  will  be 
entirely  prevented ;  where  these  conditions  do  not  obtain 
the  water  may  become  contaminated.  As  will  be  seen, 
when  the  construction  of  deep  wells  is  being  considered, 
it  is  often  exceedingly  difficult  to  keep  out  water  from  the 
more  superficial  water-bearing  strata,  which  may  have  to 
be  pierced  in  order  to  reach  the  pure  water  in  the  rocks 
below.  A  striking  instance  of  this  fact  will  be  found  in 
the  account  of  the  fatal  outbreak  of  dysenteric  diarrhoea 
at  the  Melton  Asylum  (Chapter  IX.).  The  water  tapped 
by  the  deep  well  may  itself  be  impure,  especially  if  the 


THE  POLLUTION  OF  DRINKING  WATER  22$ 

water-bearing  rock  be  fissured  and  the  outcrop  be  in  an 
inhabited  district.  If  the  fissures  are  open  or  only 
contain  freely-permeable  rocky  debris,  polluting  matters 
may  travel  considerable  distances.  In  the  Edinburgh 
Medical  Journal  for  November,  1894,  Dr.  A.  C.  Houston 
gives  an  account  of  a  well  at  Morningside,  294  feet  deep, 
which  yielded  polluted  water.  The  pollution  was  ap- 
parently due  to  the  discharge  of  sewage  into  a  quarry  800 
feet  away,  since  the  pollution  ceased  soon  after  the  sewage 
was  diverted  into  the  Edinburgh  sewers.  Several  other 
instances  of  such  pollution  have  already  been  referred  to. 

Pollution  of  Water  arising  during  Storage. — Reservoirs 
fed  by  springs  and  streams,  if  not  provided  with  some 
arrangement  for  excluding  storm  water,  may  be  contami- 
nated by  filth  carried  down  by  the  floods.  When  rivers 
are  in  flood,  the  impurities  which  had  deposited  on  the 
bottom  and  sides,  and  which  may  contain  the  specific 
organisms  of  enteric  fever,  and  possibly  of  cholera  and  other 
diseases,  are  disturbed  and  become  suspended  in  the  water, 
and  if  allowed  to  pass  into  the  storage  reservoirs  may  lead 
to  an  outbreak  of  disease,  especially  if  the  filtering  arrange- 
ments at  the  time  are  not  in  perfect  working  order.  Many 
extensive  epidemics  of  enteric  fever  have  been  attributed 
to  the  use  of  water  so  polluted.  At  Ashton-in-Makerfield 
a  recent  outbreak  of  typhoid  fever  was  attributed  by 
Dr.  Wheatley,  the  Local  Government  Board  Inspector,  to 
the  pollution  of  the  water  in  the  reservoir  by  the  manuring 
of  the  ground  immediately  surrounding  it  with  the  contents 
of  the  privies  and  middens  of  the  town.  Surface  water 
from  these  fields  actually  drained  directly  into  the 
reservoir.  During  the  latter  half  of  1893  an  epidemic  of 
typhoid  fever  occurred  in  and  around  Paisley,  affecting 
over  800  people.  Dr.  Munro,  the  County  Medical  Officer, 
attributed  it  to  the  pollution  of  the  water  supply,  and  upon 
visiting  the  reservoir  a  month  after  the  beginning  of  the 
epidemic  he  found  that  until  the  6th  of  July  there  had 


230  WATER  SUPPLIES 

existed  close  to  the  margin  of  the  water  an  inhabited  farm 
house,  "  the  drainage  or  soakage  from  which  could  only 
escape  into  the  reservoir."  Dr.  P.  Frankland,  who 
examined  the  collecting  ground  and  the  filter  beds,  proved 
that  the  filters  were  in  an  unsatisfactory  state.  In  1885 
an  outbreak  of  typhoid  fever  occurred  in  Pennsylvania. 
1,200  people  were  attacked  and  150  died.  Stampfel  states 
that  during  the  early  spring  the  dejecta  from  a  typhoid 
patient  were  thrown  upon  the  snow  lying  on  a  hill  sloping 
towards  the  source  of  the  public  water  supply.  A  sudden 
thaw  setting  in,  the  impurities  would  be  carried  down  with 
the  melted  snow.  This  occurred  on  25th  March,  and  on 
10th  April  the  epidemic  commenced.  Just  at  that  time 
the  water  from  this  particular  source  was  being  used  to  an 
unusual  extent.  Those  who  derived  water  from  other 
sources  were  not  affected. 

The  growth  of  certain  vegetable  organisms  in  open  reser- 
voirs may  result  in  the  production  of  odorous  substances 
affecting  the  whole  of  the  water.  These  have  been  already 
referred  to  in  a  preceding  chapter.  Covered  service 
reservoirs  may  have  an  overflow  connected  with  a  sewer  by 
means  of  a  trap.  If  for  a  lengthened  period  the  water 
level  never  rises  sufficiently  high  to  reach  the  overflow,  the 
evaporation  of  the  water  in  the  trap  might  unseal  the 
latter  and  allow  of  sewer  air  gaining  access  to  the  water  in 
the  reservoir.  Of  course  the  overflow  should  discharge  in 
the  open  air  and  at  some  little  distance  from  a  trapped 
gully  communicating  with  the  sewer.  Overflow  pipes  from 
house  cisterns  have  frequently  been  the  cause  of  the  con- 
tamination of  the  water  stored  therein,  from  being  directly 
connected  with  soil  pipes  or  drains,  and  outbreaks  of 
disease  have  been  attributed  to  the  use  of  such  water. 
House  cisterns  also  are  often  placed  in  situations  which 
render  the  water  liable  to  pollution.  Even  at  the  present 
day  it  is  not  uncommon  to  find  such  a  cistern  within  a 
water-closet.  Usually  they  are  placed  in  inaccessible 


THE  POLLUTION  OF  DRINKING  WATER  231 

corners  and  left  uncovered.  In  a  large  institution,  recently, 
a  series  of  cases  of  erysipelas  and  diphtheria  led  to  the 
examination  of  the  drainage,  water  supply,  etc.  The  water 
drawn  from  the  taps  within  the  buildings  was  found  upon 
analysis  to  show  signs  of  pollution,  whereas  the  water  from 
the  main  before  entering  the  premises  was  free  from 
suspicion.  When  the  cistern  was  examined,  it  was  found 
to  contain  a  considerable  amount  of  filthy-looking  sediment 
and  the  decomposing  bodies  of  a  rat  and  bird.  When  the 
cistern  had  been  thoroughly  cleaned  the  water  from  the 
taps  was  as  pure  as  that  from  the  main.  Where  the  house 
cistern  supplies  directly  the  water  used  for  flushing  the 
closets,  there  is  always  a  danger  of  air  from  the  closet  pan 
finding  its  way  into  the  cistern.  •  All  these  defects  admit 
of  simple  remedies.  The  overflow  pipe  should  terminate 
in  the  open  air;  the  water-closet  should  be  flushed  from  a 
separate  cistern;  the  house  cistern,  if  it  cannot  be  dis- 
pensed with,  should  be  tightly  covered,  placed  in  an  easily 
accessible  situation,  and  kept  perfectly  clean. 

The  materials  of  which  tanks  and  cisterns  are  composed 
may  contaminate  the  water.  New  bricks,  cement,  and 
mortar  give  up  certain  substances  to  the  water  stored 
therein,  and  if  the  cement  and  mortar  contain  road- 
scrapings,  the  dissolved  substances  may  not  be  of  an 
entirely  innocuous  character.  In  rural  districts  no  new 
house  can  be  inhabited  until  the  owner  has  obtained  from 
the  Sanitary  Authority  a  certificate  to  the  effect  that  it 
has  within  a  reasonable  distance  a  wholesome  supply  of 
water.  In  the  discharge  of  my  duties  I  have  frequently 
to  examine  water  from  recently-constructed  wells,  which, 
from  their  position  and  my  knowledge  of  the  character 
of  the  subsoil  of  the  locality  I  should  regard  as  of  satisfac- 
tory quality,  yet  I  often  find  that  such  waters  are  ex- 
cessively hard,  and  give  indications  of  the  presence  of 
organic  impurity.  The  hardness  is  due  to  the  salts 
given  up  by  brickwork,  mortar,  and  cement,  whilst  the 


232  WATER  SUPPLIES 

organic  matter  is  in  part  derived  from  the  wooden  curb  at 
the  bottom  of  the  well;  but  I  am  strongly  inclined  to 
believe  that  it  is  in  greater  part  derived  from  road- 
scrapings  which  have  been  mixed  with  the  bonding  and 
lining  material.  The  water  in  such  wells  gradually  im- 
proves in  quality  as  the  soluble  matters  are  exhausted. 
Tanks  made  for  storing  rain  water,  if  lined  with  cement, 
may  cause  the  water  to  be  very  hard  even  for  a  prolonged 
period.  Underground  tanks,  if  not  properly  constructed 
and  covered,  may  admit  impure  surface  and  subsoil  water. 
Waters  of  less  than  1°  of  temporary  hardness  dissolve  to  a 
slight  extent  both  lead  and  zinc,  and  therefore  will  act 
more  or  less  freely  upon  cisterns  lined  with  these  metals. 
Waters  with  a  temporary  hardness  of  1°  to  3°  may  at 
first  attack  a  leaden  cistern;  but  the  surface  gradually 
becomes  covered  with  a  thin  white,  opaque  deposit,  which 
protects  the  metal  from  further  action.  If  the  surface  be 
now  scoured,  the  lead  is  again  attacked.  Decomposing 
organic  matters  and  the  presence  of  air  are  believed  to 
increase  the  plumbo-solvent  action  of  a  water ;  hence,  if 
stored  in  a  dirty  cistern,  it  may  dissolve  lead  more  freely 
from  the  sides  thereof  than  from  the  surface  of  a  clean 
leaden  pipe.  Roques,*  in  a  paper  on  "  The  Perforation 
of  Zinc  Cisterns  and  the  Corrosion  of  Lead  Pipes  by 
Water,"  states  that  zinc  and  galvanised  iron  cisterns  are 
not  corroded  uniformly  but  in  well-defined  places,  which 
fact  he  attributes  to  the  galvanic  action  set  up  between 
purer  and  more  alloyed  portions  of  the  metal.  The 
presence  of  nitrogenous  matters  and  ammonia  he  found  to 
accelerate  the  action,  especially  in  the  case  of  zinc.  The 
action  was  also  most  marked  in  the  presence  of  oxygen, 
and  at  the  surface  where  the  metal  is  alternately  in  contact 
with  water  and  air.  Waters  of  over  3°  of  temporary  hard- 
ness may  with  safety  be  stored  in  either  galvanised  iron  or 

*  Bulletin  de  la  Societt  Chimique  de  Paris,  5th  June,  1880. 


THE  POLLUTION  OF  DRINKING  WATER  233 

leaden  cisterns.  Wooden  water-butts  are  an  abomination. 
Under  all  circumstances  wood  is  a  most  unsuitable  material 
of  which  to  construct  receptacles  for  storing  water;  it 
gradually  rots  and  gives  up  organic  matter  to  the  water, 
and  encourages  the  growth  of  worms  and  other  low  forms 
of  life. 

Pollution  of  Water  arising  during  Distribution. — Water, 
whilst  in  the  mains  and  service  pipes,  may  be  affected  in 
quality  either  by  its  action  upon  the  materials  of  which 
the  pipes  are  constructed,  or  by  the  insuction  of  gaseous 
and  liquid  impurities. 

Cast  iron  is  powerfully  acted  upon  by  soft  waters. 
Hence,  if  such  waters  are  distributed  through  mains  of  this 
material,  the  surface  of  the  pipe  becomes  corroded,  and  the 
water,  carrying  with  it  a  little  of  the  rust  in  suspension, 
becomes  more  or  less  turbid  and  unsightly.  The  rust 
which  forms  being  much  more  voluminous  than  the  iron 
from  which  it  is  produced,  forms  concretions  on  the  sides 
of  the  pipes,  gradually  decreasing  the  calibre,  until  they 
are  no  longer  capable  of  conveying  a  sufficient  quantity  of 
water,  or  until  the  metal  is  so  decreased  in  thickness  as  to 
be  easily  perforated  or  fractured.  By  using  pipes  which 
have  been  coated  inside  and  out  with  Angus  Smith's 
varnish  (of  pitch  and  coal-tar  oil),  this  corrosive  action  is 
almost  entirely  prevented.  The  common  method  of 
"  jointing "  water  mains  has  frequently  led  to  the 
deterioration  of  the  quality  of  the  water.  Tow  or  gaskin 
is  used  for  caulking  the  joint,  to  prevent  the  molten  lead 
running  into  the  interior  of  the  pipe,  and  at  each  joint 
therefore  more  or  less  tow  is  exposed  to  the  action  of  the 
water.  In  a  long  main  this  may  impart  a  peculiar  odour 
and  taste  to  the  water,  due  to  the  organic  matter  which 
it  tfias  dissolved.  The  Rivers  Pollution  Commissioners 
in  their  6th  Report,  page  222,  state  that  these  hemp- 
stuffed  joints  afford  a  nidus  for  the  breeding,  development, 
and  decay  of  animalculse;  so  that  the  deterioration  of  the 


234  WATER  SUPPLIES 

water  is  for  a  year  or  two  very  great,  and  continues  to  be 
perceptible  even  after  the  lapse  of  many  years.  As  an 
example  of  the  fouling  of  water  from  this  cause,  the  case 
is  quoted  of  the  inquiry  held  by  the  Board  of  Trade  in 
1869  on  account  of  the  complaint  of  the  inhabitants  of 
Putney  and  Wandsworth,  that  the  water  supplied  by  the 
Southwark  and  Vauxhall  Company  was  bad  and  unfit  for 
domestic  purposes.  It  was  found  that  the  water  was 
derived  from  a  recently-laid  main,  9J  miles  in  length, 
with  over  4,000  tow-caulked  joints.  The  result  of  the 
inquiry  showed  that  "  the  evil  complained  of  was  due 
chiefly,  if  not  entirely,  to  the  deleterious  influence  of  the 
tow  used  in  packing  the  joints  of  the  main."  Analysis 
proved  that  a  marked  quantity  of  organic  matter  was 
taken  up  by  the  water  from  the  tow. 

The  small  service  pipes  are  usually  of  lead  or  galvanised 
wrought  iron,  both  of  which  may  affect  the  water  if,  as 
we  have  previously  observed,  the  temporary  hardness  be 
very  low.  Unfortunately,  the  water  which  acts  upon  lead 
also  acts  upon  zinc;  hence  one  cannot  be  substituted  for 
the  other.  As  zinc,  unlike  lead,  is  apparently  not  a  cumu- 
lative poison,  galvanised  iron  may  be  used  instead  of  lead, 
as  possibly  the  lesser  of  two  evils.  In  many  cases  the  lead 
pipe  becomes  tarnished  and  encrusted,  and  then  is 
so  slightly,  if  at  all,  affected  by  the  water  passing  through 
it,  that  it  may  be  used  without  appreciable  risk.  Glasgow 
is  supplied  with  Loch  Katrine  water,  which  has  a  hardness 
of  less  than  1°,  and  lead  service  pipes  are  in  general  use; 
yet  lead  poisoning  is  unknown  in  that  city.  The  Man- 
chester water  supply  is  very  similar  in  character,  but  few 
cases  of  lead  poisoning  have  been  observed,  and  they  were 
probably  confined  to  persons  who  had  drunk  water 
conveyed  through  new  service  pipes.  Both  the  Manchester 
and  Glasgow  waters  act  powerfully  on  both  tarnished  and 
untarnished  lead.  Professor  W.  A.  Miller,  F.R.S.,  in  his 
evidence  before  the  Royal  Commission  on  Water  Supply, 


THE  POLLUTION  OF  DRINKING  WATER  235 

gave  it  as  his  opinion  that  such  waters  as  that  from 
Loch  Katrine,  when  passed  through  a  pipe  continuously, 
paint,  as  it  were,  the  inside  with  a  deposit  of  vegetable 
matter,  which  combines  with  the  oxide  of  lead,  and  so 
forms  a  closely  adherent  film,  which  prevents  all  change. 
The  experience  of  Glasgow  and  Manchester  has  been  very 
different  to  that  of  the  majority  of  towns  using  soft 
moorland  water.  As  an  example  of  the  more  usual  results 
following  the  use  of  these  waters,  the  experience  of  Pudsey 
may  be  cited.  The  Medical  Ofiicer  of  Health,  Dr.  Lovell 
Hunter,  in  his  report  for  1892,  says,  "  The  Local  Board  in 
1892  bought  the  plant  of  the  Calverley  District  Water 
Company.  The  moorland  water  supplied  is  soft  and 
organically  pure,  but  often  unsightly,  from  the  presence 
of  peat.  It  has,  however,  two  serious  defects :  it  is  too 
dear — a  fact  that  interferes  with  the  quantity  used,  and 
it  takes  up  lead  from  the  service  pipes."  To  remedy  the 
latter  evil,  3  grains  of  chalk  were  mixed  with  each  gallon 
of  water,  commencing  in  July.  The  water,  which  prior  to 
this  date  had  contained,  when  delivered  through  the  service 
pipes,  from  .2  to  .9  grain  of  lead  per  gallon,  was  afterwards 
found  to  yield  only  from  .07  to  .35  grain,  according  to  the 
length  of  the  service  pipe.  The  use  of  this  water  soon 
produced  a  serious  effect  upon  the  health  of  the  inhabi- 
tants. In  a  letter  received  from  Dr.  Hunter,  he  says, 
"  Anaemia  and  debility  were  the  most  common  symptoms. 
The  debility  was  peculiar;  the  patients  nearly  always 
complained  that  they  felt  as  if  they  would  sink  down  from 
weakness,  and  that  the  least  exertion  made  them  sweat 
freely.  When  the  poisoning  was  at  its  worst,  I  think  I 
may  safely  say  that  the  majority  of  the  people  had  the  blue 
gum  line  (so  characteristic  of  lead  poisoning)  without  any 
other  sign  of  poisoning.  Colic  was  also  a  common  symptom. 
Paralysis  was  not  common,  but  we  had  five  or  six  cases  of 
what  may  almost  be  called  general  paralysis,  so  helpless 
were  the  patients;  and  in  these  cases  drop-wrist  was 


236  WATER  SUPPLIES 

included,  but  I  only  heard  of  one  case  of  drop-wrist  by 
itself.  Lead  poisoning  is  a  complaint  which  may  imitate 
almost  any  other  complaint,  and  it  is  a  practical  point  to 
know  that  we  had  it  rampant  in  this  district,  and  doing 
immense  damage  to  health,  without  recognising  what  we 
were  dealing  with."  Well  waters  also  may  be  affected  by 
the  lead  piping  attached  to  the  pump.  This  is  especially 
the  case  with  waters  from  the  Bagshot  sands,  which  appear 
to  contain  very  little  carbonate  of  lime.  In  several  parts 
of  my  districts,  where  the  water  is  derived  from  these  beds, 
a  trace  of  lead  can  be  found  in  all  the  supplies  drawn 
through  a  leaden  suction  pipe.  The  Rivers  Pollution  Com- 
missioners mention  that  some  polluted  shallow-well  waters 
not  only  act  upon  lead  violently,  but  continuously,  and 
that  several  instances  of  poisoning  from  the  use  of  leaden 
pump  pipes  had  come  to  their  knowledge.  The  one  analysis 
given  of  such  a  water  shows  that  it  was  far  purer  than  the 
average  of  shallow-well  waters,  but  that  the  temporary 
hardness  was  under  1°.  When  a  galvanised  iron  pipe  was 
substituted  for  the  leaden  one,  the  water,  as  might  have 
been  expected  from  its  composition,  became  charged  with 
zinc,  and  zinc  poisoning  followed  the  lead  poisoning.  The 
so-called  tin-lined  lead  pipes  also  yield  lead  to  the  water, 
inasmuch  as  the  tin  in  the  process  of  lining  becomes 
alloyed  with  the  lead. 

As  previously  stated,  water  which  acts  upon  lead  will 
also  attack  the  zinc  coating  of  galvanised  iron.  A  case  of 
poisoning  from  this  cause  recently  came  under  my  notice. 
The  water  supply  to  a  newly-erected  country  house  was 
derived  from  a  spring  arising  at  the  edge  of  a  patch  of 
Bagshot  sand.  The  water  was  piped  from  this  spring  to 
the  house,  a  distance  of  half  a  mile,  through  galvanised 
iron  pipes.  The  only  child,  who,  prior  to  the  removal  into 
the  new  house,  had  been  perfectly  healthy,  became  a 
sufferer  from  obstinate  constipation.  At  length  suspicion 
rested  upon  the  water  supply,  probably  because  an 


THE  POLLUTION  OF  DRINKING  WATER  237 

iridescent  film  always  formed  on  its  surface  when  exposed 
in  open  vessels,  or  when  heated  in  an  open  pan.  (This  film 
is  very  characteristic  of  the  presence  of  zinc,  and  is  often 
put  down  to  a  trace  of  oil  or  grease.)  Upon  analysis  I 
found  that  the  water  contained  about  3  grains  of  carbonate 
of  zinc  per  gallon.  When  the  water  supply  was  changed, 
the  constipation  ceased.  Many  months  after,  I  again 
examined  the  water,  which  had  been  allowed  to  flow  freely 
through  the  pipe,  in  the  hope  that  it  would  speedily 
dissolve  off  the  whole  of  the  zinc ;  but  it  still  contained 
too  large  a  quantity  to  be  considered  safe  for  domestic  use. 
During  the  present  year  (1900)  I  have  found  zinc 
in  several  samples  of  water,  one  of  which  was  suspected 
to  be  the  cause  of  an  epidemic  of  diarrhoea.  I  found, 
however,  that  the  zinc  was  only  present  in  the 
water  drawn  in  the  early  morning,  doubtless  taken 
up  whilst  standing  in  the  pipes  through  the  night. 
Dr.  Heaton,  in  the  Chemical  News  (22nd  Feb.,  1884),  gives 
an  analysis  of  a  water  from  near  Llanelly,  which  is  carried 
for  half-a-mile  through  galvanised  iron  pipe.  It  was  found 
to  contain  over  6  grains  of  carbonate  of  zinc  to  the  gallon. 
Unfortunately  the  degree  of  temporary  hardness  is  not 
stated,  nor  the  reason  why  the  Medical  Officer  sent  it  for 
analysis.  Dr.  Venables,  in  the  Journal  of  the  American 
Chemical  Society*  gives  the  analysis  of  a  spring  water 
which,  after  passing  through  200  yards  of  galvanised  iron 
pipe,  and  after  being  in  use  a  year,  contained  over  4  grains 
of  zinc  carbonate  per  gallon.  The  temporary  hardness  in 
this  case  was  under  1°.  He  concludes  that,  "  when  the 
dangerous  nature  of  zinc  as  a  poison  is  taken  into  con- 
sideration, the  use  of  zinc-coated  vessels  in  connection  with 
water  or  any  food  liquid  should  be  avoided."  Wooden 
pipes,  which  were  formerly  used  for  conveying  water,  are 
quite  unsuited  for  the  purpose,  chiefly  on  account  of  the 

*  Reprinted  in  Chemical  News,  5th  January,  1885. 


238  WATER  SUPPLIES 

defective  joints.  They  are  also  said  to  rot  and  contaminate 
the  water,  but  specimens  of  such  pipes,  now  in  the  Hornsey 
Museum,  and  which  had  been  in  use  in  London  for 
probably  two  centuries,  show  no  signs  of  rotting. 

The  insuction  of  polluting  matters  into  water  mains,  and 
the  danger  arising  therefrom  does  not  seem  to  have 
received  the  attention  it  deserves.  When  the  water  supply 
is  shut  off,  as  is  done  periodically  where  the  supply  is 
intermittent,  and  occasionally,  for  various  reasons,  where 
the  supply  is  constant,  it  is  obvious  that  little  or  no  water 
can  be  drawn  from  the  mains  at  any  point  without  air  or 
water  being  drawn  in  at  other  points,  as  at  unturned  taps, 
ball  hydrants,  defects  in  joints,  perforations  through  pipes, 
etc.  Where  water-closets  are  flushed  directly  by  a  tap 
from  the  service  pipe,  should  this  tap  be  defective  or  not 
turned  off,  air,  and  possibly  filth  may  be  drawn  into  the 
pipe  from  the  closet  pan.  To  an  accident  of  this  kind 
Dr.  Buchanan  attributed  the  outbreak  of  typhoid  fever 
at  Caius  College,  Cambridge.  The  same  medical  officer, 
when  investigating  the  cause  of  the  prevalence  of  typhoid 
fever  at  Croydon  in  1875,  made  a  series  of  experiments  of 
a  very  interesting  character.  He  was  partly  led  thereto 
from  the  recorded  incident  of  bloody  water  being  drawn 
from  a  tap  at  a  house  next  door  to  a  slaughter-house.  He 
put  into  a  closet  pan  sufficient  burnt  sugar  to  colour  some 
thousand  gallons  of  water.  This  pan  was  flushed  with  a 
stool  tap.  During  the  intermission  of  the  water  supply 
the  whole  of  the  burnt  sugar  solution  was  drawn  into  the 
mains,  and,  strange  to  say,  only  from  one  house  was  a 
complaint  received  of  the  discoloration  of  the  water.  Most 
of  the  colouring  matter  must  therefore  have  travelled  a 
considerable  distance  along  the  mains,  and  have  become 
very  largely  diluted  before  reaching  the  consumers.  The 
balls  in  ball  hydrants  fall  when  the  water  pressure  is 
reduced  in  the  mains  by  drawing  water  after  the  supply 
has  been  turned  off  at  the  works.  The  boxes  are  usually 


THE  POLLUTION  OF  DRINKING  WATER  239 

placed  below  the  ground  level  as  a  protection  from  frost, 
and  are  generally  found  filled  with  dirt  which  has  washed 
in  from  the  roads.  Dr.  Kelly,  who  investigated  an  out- 
break of  typhoid  fever  which  occurred  at  West  Worthing 
in  1893,  attributed  it  to  the  pollution  of  the  water  in  a 
certain  main  by  the  insuction  of  filth  from  these  hydrant 
boxes. *  He  examined  many  of  these  hydrants  before  the 
morning  pumping  had  begun,  and  found  most  of  the  balls 
down,  and  most  of  the  boxes  half  full  of  mud.  "  It  is 
obvious/'  he  says,  •"  that  any  surface  or  road  filth  may  thus 
enter  the  mains  in  wet  weather,  and  a  person  may  drink 
impure  water  which  has  been  fouled  at  a  distant  point." 
Where  the  water  mains  are  defective,  the  insuction  may 
take  place  through  the  apertures  in  the  pipes  or  joints. 
Gas,  emanations  from  sewers,  foul  ground  air,  and  the 
water  which  had  previously  escaped  from  the  main  when 
under  pressure,  may  be  drawn  into  the  pipe  during  the 
intermission  in  the  supply.  Sewage  from  leaky  drains 
and  sewers  has  in  this  way  gained  access  to  the  water 
mains,  and  several  serious  outbreaks  of  typhoid  fever  have 
been  attributed  to  this  cause.  The  serious  and  continued 
epidemic  of  typhoid  fever  at  Mountain  Ash  (Glamorgan- 
shire) in  1887  was  attributed  by  Mr.  John  Spear,  who 
investigated  it,  to  the  pollution  of  the  water  in  a  certain 
branch  main,  and  the  distribution  of  the  disease  led  him 
to  predict  almost  the  exact  spot  where  the  contamination 
took  place.  When  the  main  at  this  point  was  laid  bare 
it  was  found  to  be  laid  alongside  and  even  through  old 
rubble  drains,  and  the  main  itself  was  here  defective.  He 
had  "  opportunities  of  observing  how  considerable  was  the 
suction  of  air  into  the  pipes  at  certain  points  after  inter- 
mission of  supply,  and,  on  its  renewal,  how  much  air, 

*  Hydrants  of  this  character  cannot  be  too  strongly  condemned.  It 
was  subsequently  found  that  water  from  the  specifically  polluted  mains 
supplying  Worthing  proper  had  been  used  for  watering  the  streets  in 
West  Worthing. 


24o  WATER  SUPPLIES 

coming  with  much  noise  and  force,  had  to  be  expelled," 
proving  that  during  intermissions  of  the  service  serious 
contamination  of  the  water  of  the  special  main  must  have 
occurred. 

Dr.  M.  A.  Adams,  F.R.C.S.,  Medical  Officer  of  Health 
for  the  Borough  of  Maidstone,  in  his  Annual  Report  for 
1894  states  that  he  found  in  May  that  the  water  from  a 
particular  hydrant  was  polluted.  Upon  investigating  the 
cause,  the  main  was  found  to  be  defective  at  two  points 
near  a  disused  drain.  Dr.  Adams  explains  the  insuction  of 
foul  matters  by  stating  that  there  was  a  tendency  for  this 
service  pipe  to  empty  itself  in  favour  of  the  lower  placed 
hydrants,  and  when  the  taps  at  these  lower  places  were 
shut  off,  a  wave  of  water  pressure  was  sent  forward  to  the 
higher  level ;  when  this  wave  reached  the  hydrant 
implicated,  the  water  recoiled  upon  itself,  and  set  up  a 
sudden  and  strong  retreating  current  in  the  opposite 
direction,  which  produced  the  insuction.  He  adds,  "  This 
seemingly  small  matter  ought  not  to  be  lost  sight  of ;  it 
teaches  a  practical  lesson  in  hydraulics  of  the  greatest 
sanitary  importance." 

Where  water  mains  are  directly  connected  with  the 
sewers  in  order  to  supply  water  for  flushing  purposes,  there 
is  always  a  danger  of  sewer  air  gaining  access  to  the  mains ; 
hence  such  a  mode  of  flushing  should  be  discontinued. 

Not  only  is  polluting  matter  drawn  into  service  pipes 
and  mains  during  intermissions  in  the  supply,  but  even 
when  the  pipes  are  running  full  such  insuction  is  possible. 
Our  knowledge  of  this  subject  is  entirely  due  to  Dr. 
Buchanan's  investigations,  made  in  connection  with  the 
Croydon  epidemic,  previously  referred  to.  He  found — 
"  (1)  The  lateral  in-current  is  freely  produced  when  the 
water  pipe  is  descending,  and  when  the  pipe  beyond  the 
hole  is  unobstructed;  (2)  If  the  force  of  water-flow  in  a 
descending  pipe  be  moderate,  a  moderate  degree  of  obstruc- 
tion beyond  the  hole  does  not  prevent  the  in-current; 
(3)  In  horizontal  pipes  of  uniform  calibre,  when  the  flow  is 


THE  POLLUTION  OF  DRINKING  WATER  241 

Strong,  or  the  pipe  beyond  the  hole  is  long,  or  when  the 
end  of  the  pipe  is  at  all  turned  upwards,  the  in-current 
does  not  take  place;  but  (4)  Momentary  interference  with 
flow  a  tergo,  or  momentary  reduction  of  obstruction 
a  f route,  allows  a  momentary  in-current  through  the  hole ; 
(5)  In-current  through  a  lateral  hole  takes  place  with 
incomparably  greater  ease  when  the  hole  is  made  at  a 
point  of  constriction  of  the  water  pipe." 

Potable  water  may  also  be  contaminated  by  the  barrels, 
skins,  etc.,  in  which  it  is  conveyed,  when  distributed  by 
these  means.  Where  the  supply  is  not  laid  on  to  the 
houses  it  is  often  stored  in  buckets,  open  jars,  tubs,  and 
other  vessels,  which  may  be  unsuitable  from  the  difficulty 
of  keeping  them  clean,  or  on  account  of  the  material  of 
which  they  are  composed.  The  water  in  them  may  also 
be  exposed  to  foul  emanations  from  drains,  closets, 
accumulations  of  filth,  or  to  dust  from  the  proximity  to 
ash-places,  and  so  become  polluted.  In  eastern  countries 
many  holy  wells  and  pools  from  which  pilgrims  drink  are 
defiled  by  the  water  being  poured  over  the  people  and 
being  allowed  to  run  back  into  the  well  or  pool,  or  by  the 
pilgrims  actually  bathing  in  the  water.  In  these  countries 
also  the  tanks  which  contain  the  drinking  water  are  often 
used  for  rinsing  clothes  and  for  bathing  purposes.  Such 
modes  of  pollution  rarely  occur  in  this  country,  but  people 
have  been  known  to  bathe  in  reservoirs  used  for  supplying 
drinking  water,  and  dogs  are  sometimes  drowned  therein. 

From  the  multitude  of  ways  in  which  water  may  be 
polluted — at  its  source,  during  storage,  during  its  passage 
through  the  mains,  and  within  the  premises  which  it 
supplies — it  follows  that  not  only  must  the  utmost  care 
be  exercised  in  the  construction  of  works,  and  in  the 
distribution  of  the  water,  but  that  this  must  be  supple- 
mented by  a  vigilant  and  continuous  supervision  over 
every  detail,  if  the  purity  of  the  supply  is  to  be  kept  above 
suspicion. 

16 


CHAPTER   XII. 

THE  SELF-PURIFICATION  OF  RIVERS. 

IN  previous  chapters  frequent  reference  has  been  made 
to  this  subject;  but  it  is  one  of  such  far-reaching  import- 
ance as  to  merit  special  and  separate  consideration.  For 
all  practical  purposes  the  materials  polluting  our  streams 
may  be  divided  into  two  groups — the  waste  products  of 
manufacturing  processes,  and  the  contents  of  drains  and 
sewers,  the  latter  being  by  far  the  more  dangerous.  When 
the  contaminating  matters  from  factories  become  so 
diluted  by  the  water  into  which  they  are  discharged, 
or  the  water,  after  receiving  it,  undergoes  such  a 
process  of  self-purification  that  it  presents  no  evidence 
of  pollution  to  the  senses,  and  chemical  and  bacterio- 
logical analysis  reveals  nothing  objectionable,  there  is 
no  risk  incurred  in  using  it  for  drinking  purposes. 
Where  the  material  which  fouls  the  river  contains  the 
waste  products  of  human  life,  of  the  body  in  disease  and 
health, — in  other  words,  when  sewage  is  the  polluting 
matter, — this  condition  no  longer  obtains.  Ample  proof 
has  been  already  adduced  of  the  fact  that  dilution  and 
purification  may  have  taken  place  to  such  a  degree  that 
the  most  careful  analysis  can  detect  no  element  of  danger, 
yet  that  the  water  may  be  practically  poisonous  and 
capable  of  causing  most  serious  epidemics  of  disease.  The 
question  in  which  we  are  interested  therefore  is,  not 
whether  a  fouled  river-water  may  regain  its  pristine  appear- 
ance of  purity,  but  whether  it  can  ever  again  become 
absolutely  safe  for  drinking  purposes.  Ordinary  observation 
enables  us  to  answer  the  first  question  in  the  affirmative; 

(242) 


THE  SELF-PURIFICATION  OF  RIVERS  243 

all  the  researches  of  chemists  and  bacteriologists  since  the 
days  when  the  Rivers  Pollution  Commissioners  first  experi- 
mentally studied  this  subject,  have  failed  to  answer  the 
second.  On  the  one  hand,  we  have  the  Commissioners 
of  Metropolitan  Water  Supply  so  satisfied  that  sewage- 
polluted  river  water  can  be  rendered  safe  for  human 
consumption  that  they  recommend  the  metropolis  to  draw 
still  further  from  this  source,  and  on  the  other  we  have 
the  Massachusetts  State  Board  of  Health  about  the  same 
time  reporting  that  the  results  of  their  investigation  of 
repeated  outbreaks  of  typhoid  fever  in  cities  using  such 
waters  served  to  confirm  the  truth  of  the  saying  that 
"  no  river  is  long  enough  to  purify  itself."  It  will  be 
remembered  that  the  Rivers  Pollution  Commissioners  came 
to  the  conclusion,  from  the  results  of  their  experiments, 
that  "  there  is  no  river  in  the  United  Kingdom  long 
enough  to  effect  the  destruction  of  sewage  by  oxidation." 
The  experiments  and  observations  upon  which  this  opinion 
was  based  are  recorded  in  their  6th  Report,  and  have  now 
become  historical.  Experimenting  first  with  the  Irwell 
and  Mersey,— rivers  so  notoriously  polluted  by  sewage  and 
other  refuse  organic  matters  that  "  ordinary  aquatic  life 
is  entirely  banished  from  their  waters/' — they  found,  after 
making  all  possible  corrections  for  dilution,  etc.,  that  in 
the  Irwell  a  flow  of  11  miles  reduced  the  organic  carbon 
by  0  to  29.6  per  cent.,  and  the  organic  nitrogen  by  0  to  11.8 
per  cent.  In  the  Mersey  a  flow  of  13  miles  reduced  the 
former  by  0  to  20.8  per  cent.,  and  the  latter  by  13.2  to  17.9 
per  cent.  Selecting  the  Thames  as  a  much  less  polluted 
river,  samples  were  taken  about  a  quarter  of  a  mile  below 
where  it  is  joined  by  the  Kennet,  and  again  just  above  the 
Shiplake  Paper  Mills.  These  points  were  selected  because 
in  the  four  intervening  miles  the  river  does  not  receive  any 
other  affluent  or  pollution  of  importance.  The  analytical 
results  showed  that  even  under  very  favourable  circum- 
stances the  reduction  in  the  proportion  of  organic  matter 


244  WATER  SUPPLIES 

was  very  small,  "  so  minute  indeed  that,  even  assuming  it 
to  go  on  at  the  same  rate  by  night  and  day,  in  sunshine 
and  gloom,  it  would  require  a  flow  of  70  miles  to  destroy 
the  organic  matter."  To  exclude  certain  elements  of 
uncertainty,  diluted  London  sewage  was  next  experimented 
with.  It  was  agitated  with  air  and  then  allowed  to  syphon 
in  a  slender  stream  from  one  vessel  to  another,  exposed  to 
light,  and  falling  each  time  through  3  feet  of  air.  The 
results  indicated  approximately  the  effect  of  oxidation 
which  would  be  produced  by  the  flow  of  a  stream  containing 
10  per  cent,  of  sewage  for  96  and  192  miles  respectively, 
at  the  rate  of  one  mile  per  hour.  By  the  flow  of  96  miles 
the  organic  carbon  was  reduced  by  6.4  per  cent.,  and  the 
organic  nitrogen  by  28.4  per  cent.,  whilst  the  flow  of  192 
miles  reduced  the  former  25.1  per  cent.,  and  the  latter  33.5 
per  cent.  Fresh  urine  and  deep  chalk-well  water  were 
next  mixed  together  and  submitted  to  similar  treatment. 
Still  less  effect  was  produced;  the  carbon  was  but  slightly 
reduced,  whilst  the  nitrogen  showed  an  actual  increase. 
Finally,  the  results  were  checked  by  the  examination  of 
the  gases  dissolved  in  dilute  sewage  (5  per  cent.)  after 
standing  for  different  periods  in  accurately-stoppered 
bottles  exposed  to  diffused  daylight  at  a  temperature  of 
about  17°  C.  The  dissolved  oxygen  gradually  disappeared, 
but  so  slowly  that  "  so  far  from  sewage  mixed  with  twenty 
times  its  volume  being  oxidised  during  a  flow  of  10  or  12 
miles,  scarcely  two-thirds  of  it  would  be  so  destroyed  in  a 
flow  of  168  miles,  at  the  rate  of  1  mile  per  hour,  or  after 
the  lapse  of  a  week." 

Weight  of  Dissolved 

Oxygen  in  100,000 

Parts  of  Water. 

•946         ....     Immediately  after  Mixture 

•803         .         .         .         .         .         .  After  24  hours 

•616 „      48      „ 

•315 „      96      „ 

•201         • „    120      „ 

•080         .         ."•'•-.         .         .         .  „    144      „ 

•036  ,    168 


THE  SELF-PURIFICATION  OF  RIVERS  245 

The  Commissioners  believed  that  it  was  the  clarification 
by  subsidence  which  takes  place  in  nearly  all  rivers,  which 
had  led  to  the  belief,  so  general,  but  erroneous,  in  the  rapid 
self-purifying  power  of  running  water.  Their  conclusions, 
however,  were  disputed  by  the  late  Dr.  Tidy  and  others; 
but  inasmuch  as,  at  this  period,  the  part  played  by  the 
minute  forms  of  animal  and  vegetable  life  in  the  process  of 
purification  was  unknown,  many  of  the  experiments  which 
they  recorded  have  now  little  or  no  interest.  One  set  of 
observers  held,  with  the  Commissioners,  that  purification 
where  it  took  place  was  chiefly  due  to  the  deposition  of 
suspended  impurities,  others  contended  that  much  of  the 
dissolved  organic .  matter  also  disappeared.  This  latter 
view  was  strongly  supported  by  the  report  of  Drs.  Brunner 
and  Emmerick  (1875)  on  the  river  Isar  as  it  flows  through 
Munich.  They  took  every  precaution  to  render  the  results 
trustworthy,  estimating  the  quantity  and  strength  of  the 
sewage  and  other  refuse  matters  entering  the  river  from 
the  city  sewers,  and  making  due  allowance  for  the  effect  of 
dilution  by  its  tributaries.  The  results  of  analyses, 
inspection,  and  calculation  proved  that  the  river  water  two 
hours'  flow  below  Munich  was  practically  as  pure  as  the 
water  above  the  city,  or,  in  other  words,  that  all  the 
dissolved  and  suspended  impurities  cast  into  it  at  Munich 
had  disappeared.  The  former  view — viz.,  that  subsidence 
and  dilution  are  the  main  factors  in  producing  the 
so-called  self-purification — is  still  upheld  by,  amongst  others, 
Professor  Percy  Frankland.  He  undertook  a  series  of 
experiments  to  test  this  point  in  connection  with  the 
Thames,  taking  samples  of  the  water  flowing  in  the  river 
from  different  points  on  the  same  day.  One  day  at  Oxford, 
Reading,  Windsor,  and  Hampton;  on  another  day  at 
Chertsey  and  Hampton,  etc.  His  analyses  of  these  waters 
are  given  in  a  paper  contributed  to  the  International 
Congress  of  Hygiene,  entitled  "  The  Present  State  of  our 
Knowledge  concerning  the  Self-Purification  of  Rivers,"  and 


246  WATER  SUPPLIES 

he  concludes,  "  From  the  analytical  table  it  will  be  seen 
that  the  idea  of  any  striking  destruction  of  organic  matter 
during  the  river's  flow  receives  no  sort  of  support  from  my 
experiments ;  the  evidence  is  in  fact  wholly  opposed  to  any 
such  supposition."  At  first  sight  it  appears  strange  that 
such  skilled  observers  should  arrive  at  conclusions  so 
diametrically  opposed ;  but  the  investigation  is  beset  with 
difficulties,  some  practically  insurmountable.  The  water 
at  different  points  is  not  the  same ;  even  if  time  be  allowed 
for  the  water  first  sampled  to  reach  the  subsequent 
sampling  stages,  it  will  be  more  or  less  diluted  by  ground 
water  or  by  tributary  streams,  and  receive  additional 
polluting  matter  along  its  course.  The  insoluble  matter  in 
suspension,  or  on  the  bed  and  sides  of  the  river,  may  by 
its  decomposition  be  rendered  soluble ;  hence,  unless  the 
rate  at  which  the  soluble  matters  are  oxidised  and 
destroyed  is  greater  than  that  at  which  the  insoluble  or- 
ganic material  is  rendered  soluble,  the  analysis  of  the  water 
will  show  no  improvement,  or  in  fact  may,  as  in  Professor 
Frankland's  experiments,  show  even  a  deterioration.  Such 
deterioration  is  therefore  no  proof  that  a  process  of  oxida- 
tion is  not  taking  place ;  its  true  interpretation  is  probably 
the  one  just  given.  This  is  confirmed  by  the  experiments 
of  Sir  F.  Abel,  Dr.  Odling,  Dr.  Dupre,  and  Mr.  Dibdin,  on 
the  oxygenation  of  the  Thames  water.  "  They  found  that 
each  1,000  million  gallons  of  water  between  Blackwall  and 
Purfleet  lost  from  25  to  35  tons  of  oxygen,  and  retained 
oxygen  to  the  extent  of  from  5  to  15  tons.  The  quantity 
of  water  passing  Erith  upwards  in  the  upward  flow  of  the 
tide  was  estimated  by  the  engineers  to  be  40,000  million 
gallons.  This  should  contain  1,600  tons  of  oxygen; 
it  was  found  to  contain  only  400  tons;  thus  1,200  tons 
must  have  destroyed  thousands  of  tons  of  dry  organic 
matter,  altogether  disregarding  the  oxygen  the  river  was 
absorbing  from  the  atmosphere  during  the  whole  time  the 
oxiclation  was  going  on.  The  experiments  of  M.  Qeradin 


THE  SELF-PURIFICATION  OF  RIVERS  247 

confirm  these  observations;  they  are  published  in  Le 
Rapport  sur  V  Alteration  la  Corruption  et  I'assouvisse- 
ment  des  Rivieres,  and  refer  to  the  river  Seine.  This  river 
before  it  reaches  Paris  contains  its  full  amount  of  oxygen ; 
when  it  gets  to  Paris  the  greater  proportion  of  the  oxygen 
is  at  once  removed,  and  this  removal  can  only  take  place 
by  its  use  in  the  oxidation  of  organic  matter;  a  few 
kilometres  farther  on  the  river  is  found  to  again  contain  its 
normal  quantity  of  oxygen,  which  fact  is  accounted  for  by 
the  organic  matter  being  disposed  of." — Professor  W.  R. 
Smith,  "  River  Water  as  a  Source  of  Domestic  Water 
Supply."  Journal  of  State  Medicine,  April,  1894. 

The  balance  of  evidence  is  decidedly  on  the  side  of  those 
who  uphold  the  theory  of  self-purification,  and  the  diverse 
conclusions  arrived  at  by  different  observers  can  be 
accounted  for  by  the  varied  and  often  imperfect  character 
of  the  experiments,  and  by  the  diverse  conditions  which 
obtain  in  different  streams.  That  river  water,  grossly 
befouled  by  sewage  in  its  higher  reaches,  becomes  a  few 
miles  lower  down  so  pure,  from  a  chemical  point  of  view, 
as  to  be  certified  by  the  most  eminent  analysts  to  be  fitted 
for  all  domestic  purposes,  and  is  actually  so  used  by  millions 
of  our  population,  is  a  fact  which  cannot  be  gainsaid. 
Whether  this  process  of  purification  be  merely  due  to 
sedimentation  and  dilution,  or  to  these  factors,  assisted  by 
oxidation,  is,  however,  a  matter  of  trifling  importance, 
since  it  is  now  fully  recognised  that  the  disease-producing 
material  is  not  the  dead  organic  matter  in  solution,  but  the 
living  organisms  in  suspension.  The  problem  is  not  a 
chemical  one,  but  a  biological  one.  If  the  specific  disease- 
producing  bacteria  can  be  carried  long  distances  by  streams, 
it  matters  very  little  whether  they  are  accompanied  by  an 
increased  or  decreased  amount  of  the  soluble  impurities 
which  were  introduced  therewith.  Unfortunately  biologists 
differ  as  widely  as  chemists  in  their  views,  some  contending 
that  a  biologically  impure  water  may,  by  a  few  miles'  flow. 


248  WATER  SUPPLIES 

supplemented  by  some  process  of  sand  nitration,  be 
rendered  biologically  pure,  whilst  others  consider  that  the 
water  of  a  river  specifically  infected  at  any  point  cannot 
afterwards  be  rendered  safe  for  domestic  purposes  by  any 
such  means.  The  opinion  of  the  biologists  who  hold  the 
latter  view  is  supported  by  a  large  mass  of  evidence  proving 
that  many  epidemics  of  typhoid  fever  and  cholera  in  this 
country,  in  the  United  States,  and  elsewhere,  were  due  to 
the  use  of  river  water  which  had  been  polluted  many  miles 
above  the  intake  of  the  water  supplied  to  the  populations 
amongst  which  the  outbreaks  occurred  (vide  Chapter  IX.). 
As  an  example  of  the  evidence  adduced  in  support  of  the 
former  view,  may  be  cited  the  Report  made  by  the  Imperial 
Board  of  Health  in  Mecklenburg  on  the  water  supplied  to 
the  town  of  Rostock.  This  town  takes  its  water  from  the 
river  Warnow,  which,  80  kilometres  above,  is  polluted  by 
the  sewage  of  the  city  of  Gustrow.  According  to  Herr 
Ktimniel,*  "  The  Imperial  Board  of  Health  sent  a  com- 
mittee to  investigate  this  matter,  including  an  eminent 
biologist,  and  these  gentlemen  made  a  trip  up  the  Nebel 
and  Warnow  from  Rostock  to  Giistrow.  .  .  .  They  tested 
the  water  at  various  places,  from  above  the  town  of  Gustrow 
down  to  the  Rostock  Waterworks.  They  found  that,  though 
the  town  of  Gustrow  deteriorated  the  water  very  much,  and 
that  the  water  two  kilometres  below  was  polluted  much 
more  by  a  large  sugar  manufactory,  the  number  of  microbes 
above  the  town  of  Gustrow,  and  that  25  kilometres  below 
the  town  and  below  the  sugar  manufactory,  was  nearly 
the  same ;  that  whilst  in  the  -interval  the  number  of 
microbes  had  increased  to  48,000  in  a  cubic  centimetre, 
the  number  was  again  reduced  to  about  200 ;  and  at  last, 
just  above  Rostock,  where  the  river  was  said  to  have  been 
deteriorated  by  the  sewage  of  the  town  above,  the  number 
of  microbes  was  less  than  it  was  above  the  town  of  Gustrow, 

*  Proceedings  of  International  Congress  of  Hygiene,  vol.  vii.,  p.  183. 


THE  SELF-PURIFICATION  OF  RIVERS  249 

and  no  town  at  all  was  situated  above  the  point  where  the 
first  test  of  the  water  was  taken.  This  experiment  was 
made  twice — once  during  the  summer,  and  the  second  time 
in  October,  1890.  The  result  of  the  inquiry  had  been 
that  the  Imperial  Board  had  declared  the  town  of  Gustrow 
might  send  its  sewage  water  into  the  river." 

On  the  opposite  side  we  may  adduce  the  Report  of  the 
Massachusetts  State  Board  of  Health  on  the  Outbreaks  of 
Typhoid  Fever  at  Lawrence,  Lowell,  and  Newburyport, 
referred  to  in  Chapter  IX.  In  the  Newburyport  epidemic 
the  typhoid  bacilli  must  have  travelled  from  Lawrence,  a 
distance  of  over  twenty  miles.  The  Royal  Commission  on 
Metropolitan  Water  Supply,  notwithstanding  the  amount 
of  evidence  given  by  bacteriological  experts,  felt  bound  to 
fall  back  upon  the  "  evidence  from  experience  "  in  order 
to  enable  them  to  decide  whether  the  Thames  could  safely 
continue  to  be  used  as  the  source  of  water  supply  to  the 
city;  but  from  their  report  it  is  quite  evident  that  even 
on  theoretical  grounds  they  regarded  the  danger  of  dissemi- 
nating typhoid  fever  in  London  by  the  use  of  water  from 
the  Thames  and  Lea  as  being  exceedingly  remote.  Selecting 
the  year  of  highest  mortality  from  typhoid  fever  which  has 
been  recorded  in  recent  years,  allowing  seven  attacks  for 
each  fatal  case,  and  assuming  that  the  whole  of  the 
discharges  from  all  the  cases  in  the  two  valleys  passed 
directly  into  the  rivers  at  the  period  of  smallest  flow, 
there  would  be  one  typhoid  case  in  the  Thames  valley  to 
a  mass  of  water  5  miles  in  length,  100  yards  in  width,  and 
6  feet  in  depth,  and  in  the  Lea  valley  to  a  similar  body  of 
water  3  miles  in  length.  But  as  only  a  very  small 
proportion  of  such  discharges  ever  reach  the  rivers,  the 
degree  of  dilution  must  be  much  more  considerable.  This 
is  an  attempt  at  a  reductio  ad  absurdum  argument,  such 
as  Dr.  Edwards  applied  to  the  Merrimac  River  (p.  155). 
The  danger  arising  from  the  flooding  of  ditches  and  pools 
and  the  washing  down  of  the  contents  by  heavy  rains,  is 


25o  WATER  SUPPLIES 

said  to  be  scarcely  appreciable,  since  the  quantity  of 
typhoid  matter  which  would  in  this  manner  reach  the 
streams  must  be  excessively  small,  and  a  still  smaller 
amount  will  have  retained  its  power  of  setting  up  disease. 
Typhoid  dejecta  lose  their  virulence  after  a  few  days,  fifteen 
being  probably  the  maximum,  and  as  the  typhoid  bacillus 
does  not  form  spores,  it  is  only  from  typhoid  dejecta  of 
very  recent  deposit  that  any  danger  is  to  be  appre- 
hended, and  this  clearly  reduces  very  greatly  the  supposed 
risk  of  specific  pollution  of  the  water  in  times  of  floods. 
At  such  times  also  the  volume  of  river  water  is  vastly 
augmented,  and  floods  occur  chiefly  at  a  time  when  the 
temperature  of  the  water  is  too  low  to  favour  the  develop- 
ment of  the  bacilli,  and  when  typhoid  fever  is  least 
prevalent.  The  Commissioners  also  regard  typhoid  fever 
as  being  an  exclusively  human  affection,  and  that 
consequently  the  pollution  of  water  by  animal  manure, 
however  objectionable  it  may  be  on  other  grounds,  cannot 
be  regarded  as  a  possible  source  of  such  disease.  Pathogenic 
bacteria  in  water  are  in  an  unnatural  medium,  and  whilst 
the  natural  water  bacteria  increase  rapidly,  the  former 
undergo  rapid  attenuation  and  loss  of  virulence,  and,  being 
worsted  in  the  struggle  for  existence,  they  speedily 
succumb.  Direct  sunlight  also  destroys  these  bacteria,  and 
even  diffused  light  reduces  their  vitality. 

The  effect  of  the  sun's  rays  upon  the  organisms  found  in 
water  has  been  studied  by  many  observers.  Dr.  Procacci 
exposed  water  in  deep  cylinders  to  the  nearly  vertical  rays 
of  the  sun,  and  found  that  all  the  organisms  in  the  water 
up  to  a  certain  depth  were  killed.  After  three  hours' 
exposure  the  water  in  the  cylinders  to  1  foot  depth  was 
nearly  sterile,  whilst  at  a  depth  of  2  feet  they  were 
unaffected.  Professor  Buchner  exposed  gelatine  plates 
sown  with  typhoid  bacilli  in  water  at  various  depths  for  a 
period  of  four  and  a  half  hours,  and  found  that  all  those 
plates  covered  with  less  than  5  feet  of  wa.ter  were  sterilised, 


THE  SELF-PURIFICATION  OF  RIVERS  251 

Those  exposed  at  a  depth  of  10  feet  were  not  affected. 
Percy  Frankland  has  proved  that  in  the  Thames  and  Lea 
there  are  often  twenty  times  more  organisms  present  in  the 
water  in  winter  than  in  summer,  but  this  he  thinks  may 
in  part  be  due  to  the  greater  proportion  of  spring  water 
contained  in  the  streams  in  summer,  since  spring  water 
contains  comparatively  few  organisms.  When  a  little 
common  salt  is  added  to  water  the  sterilising  effect  of  the 
sun's  rays  is  said  to  be  increased. 

With  reference  to  the  great  variation  in  the  number  of 
bacteria  in  river  water  during  the  course  of  the  year, 
Professor  P.  Frankland,  in  his  Report  on  Metropolitan 
Water  Supply,  1894,  says,  "  that  the  number  of  microbes 
in  Thames  water  is  determined  mainly  by  the  rate  of  the 
flow  of  the  river,  or,  in  other  words,  by  the  rainfall,  and 
but  slightly,  if  at  all,  by  either  the  presence  or  absence  of 
sunshine,  or  a  high  or  low  temperature." 

Dr.  D.  Harvey  Attfield  (Brit.  Med.  Journ.,  17th  June, 
1893)  describes  the  results  of  a  series  of  experiments 
undertaken  by  him  in  Munich  to  ascertain  the  effect  of 
Infusoria  upon  the  bacteria  in  polluted  water.  He  con- 
cludes that  "  Infusoria  would  seem  to  have  some  powerful 
influence  in  the  getting  rid  of  bacteria,  and,  possibly,  so 
aiding  in  the  '  self-purification  '  of  water." 

During  the  process  of  sedimentation  also  a  large  propor- 
tion of  the  bacteria  are  deposited.  Professor  P.  Frankland 
has  shown  that  in  the  process  of  softening  water  by  the 
addition  of  lime,  98  per  cent,  of  these  organisms  may  be 
removed  in  the  precipitate.  In  some  recent  experiments 
made  by  me  in  connection  with  a  large  public  water  supply, 
I  found  that  the  micro-organisms  increased  very  rapidly  in 
the  softened  water,  so  that  in  a  few  hours  there  were  more 
bacteria  in  it  than  in  the  unsoftened  water.  The  investiga- 
tion was  undertaken  because  the  softened  water  when 
submitted  to  bacteriological  examination  was  almost 
invariably  found  to  contain  more  organisms  than  the 


252  WATER  SUPPLIES 

original  water ;  moreover,  it  also  contained  traces  of 
nitrites.  The  lime  used  was  sterile.  It  contained 
decided  traces  of  nitrites,  and  was  probably  made 
from  a  limestone  containing  a  trace  of  nitrates.  In 
the  river  water  as  supplied  to  London  no  patho- 
genic bacteria  have  ever  been  discovered.  It  is 
admitted  by  most  bacteriologists  also*  "  that  small  doses 
of  cholera  and  typhoid  poison  may  be  swallowed  with 
impunity,  and  some  even  believe  that  these  small  doses 
act  as  a  vaccine  and  render  the  imbiber  immune.  Theoreti- 
cally, therefore,  the  danger  of  an  epidemic  of  typhoid  fever, 
or  even  of  cholera,  from  the  use  of  Thames  and  Lea  water 
would  seem  to  be  remote,  especially  when  the  additional 
safeguard  of  careful  sand  filtration  is  introduced.  Bacterio- 
logy, however,  is  in  its  infancy,  and  our  views  on  many  of 
the  above  points  may  have  to  be  considerably  modified ; 
and  whilst  the  "  evidence  of  experience  "  in  London  has  so 
far  justified  the  conclusion  at  which  the  Commissioners 
have  arrived,  the  same  kind  of  evidence,  according  to>  most 
trustworthy  observers  in  other  towns  using  polluted  river 
water,  leads  to  a  very  different  conclusion.  The  general 
acceptation  of  the  Commissioners'  views  with  reference  to 
the  use  of  sewage-contaminated  streams  would  be  a  great 
national  misfortune,  and  would,  it  is  to  be  feared,  impede 
the  action  of  sanitary  authorities  in  their  efforts  to  secure 
the  freedom  of  our  rivers  from  pollution  by  sewage.  The 
Commissioners,  doubtless,  never  intended  that  their  con- 
clusions should  apply  to  any  other  rivers  than  the  Thames 
and  the  Lea,  and  this  fact  should  be  carefully  borne  in 
mind,  since  the  acceptance  as  a  general  principle  of  a  view 
which  is  applicable  only  to  a  particular  case  is  illogical  and 
may  bring  about  disastrous  results. 


CHAPTER  XIII. 

THE  PURIFICATION  OF  WATER  ON  THE  LARGE  SCALE. 

THE  water  derived  from  deep  wells,  springs,  and  the 
subsoil  rarely,  if  ever,  requires  filtration  or  any  other  form 
of  purification.  Surface  water,  if  collected  in  sufficiently 
large  lakes  or  reservoirs,  usually,  by  sedimentation,  becomes 
so  clarified  as  to  require  no  further  treatment.  As 
examples  may  be  mentioned  the  water  supplies  to  Glasgow 
and  Liverpool,  derived  from  Loch  Katrine  and  Vyrnwy 
Lake  respectively,  neither  of  which  is  subjected  to  any 
form  of  filtration,  the  mere  subsidence  of  the  suspended 
matters  which  enter  the  lakes  with  the  surface  drainage 
effecting  all  the  purification  which  is  necessary.  River 
water,  even  if  collected  in  reservoirs  sufficiently  large  to 
hold  several  days'  supply,  is  rarely  sufficiently  purified  by 
sedimentation  to  be  adapted  for  use  without  filtration  or 
some  other  process  of  purification.  The  collection  of  water 
in  large  reservoirs  not  only  permits  the  suspended  matters, 
living  and  dead,  to  subside,  but  the  detention  of  the  water 
in  such  receptacles  affords  time  for  the  pathogenic  organ- 
isms which  may  be  present  to  lose  their  vitality,  by  the 
action  of  light,  or  "by  the  deleterious  action  exerted  upon 
them  by  the  harmless  water-bacteria "  (P.  Frankland). 
On  the  other  hand,  the  storage  of  water  in  large  open 
reservoirs  has  its  disadvantages,  as  will  be  pointed  out  when 
the  storage  of  water  is  being  considered.  All  other  pro- 
cesses of  purification,  such  as  boiling,  distillation,  and 
precipitation,  are  only  applicable  in  special  cases  or  on  the 
small  scale ;  and  even  after  the  water  has  been  submitted 

(253) 


254  WATER  SUPPLIES 

to  these  processes,  it  usually  requires  filtering,  either  to 
clarify  it  or  render  it  palatable.  Hence  filtration  is  by 
far  the  most  important  method  of  purification,  and  an 
accurate  appreciation  of  the  factors  necessary  to  ensure 
that  this  is,  under  all  circumstances,  as  complete  as 
possible,  is  absolutely  necessary  if  our  polluted  rivers  are 
to  continue  to  furnish  the  water  supplied  to  our  large 
centres  of  population.  Until  quite  recently,  the  effect  of 
filtration  had  been  considered  exclusively  from  the  chemical 
point  of  view,  and  that  modification  which  decreased  most 
materially  the  proportion  of  organic  carbon  or  organic 
nitrogen  or  albuminoid  ammonia  was  regarded  as  being  the 
most  satisfactory.  Inasmuch  as  this  decrease  was  never 
very  large,  the  process  was  not  looked  upon  with  much 
favour  or  regarded  as  of  very  great  importance,  and  hence 
was  often  performed  in  a  very  careless  and  haphazard 
manner.  Bacteriological  research,  however,  having  demon- 
strated that  certain  specific  diseases  were  caused  by  living 
organisms,  some  of  which  might  enter  the  system  with  the 
drinking  water,  greater  attention  was  paid  to -the  subject, 
and  efforts  were  made  to  secure  greater  clarification  and 
transparency,  the  results  being  judged  by  the  examination 
of  samples  of  the  water  in  long,  glass  cylinders.  By  this 
means  some  of  the  more  important  conditions  necessary  to 
ensure  the  removal  of  the  suspended  matters  were 
discovered.  Further  bacteriological  progress,  however, 
succeeded  in  demonstrating  that  water  which  appeared 
by  such  a  test  to  be  perfectly  clarified  might  still  contain 
very  large  numbers  of  those  excessively  minute  organisms, 
bacteria,  certain  of  which  are  capable  of  causing  disease; 
and  it  is  now  generally  acknowledged  that  a  filter 
which  is  capable  of  effecting  almost  perfect  oxidation  of 
the  dead  organic  matter  in  a  water,  rendering  it  pure  from 
the  chemist's  point  of  view,  may  yet  permit  of  specific 
bacilli  passing  through  in  large  numbers.  Evidently, 
therefore,  neither  chemistry  nor  the  physical  test  of 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        255 

transparency  can  determine  whether  any  process  of  nitra- 
tion is  efficient.  We  are,  therefore,  compelled  to  resort  to 
the  bacteriological  test,  by  which  we  can  obtain  some 
approximate  idea  of  the  quantity  and  character  of  the 
organisms  which  have  succeeded  in  passing  through  the 
filter  beds.  Much  remains  yet  to  be  discovered  in  this 
science  before  the  results  of  bacteriologists  can  be  implicitly 
relied  upon.  The  confidence  of  the  Worthing  authorities  in 
the  bacteriological  examination  of  their  water  supply  proved 
to  be  misplaced.  We  have,  however,  at  present  nothing 
else  so  trustworthy,  and  as  the  study  of  the  process  of 
filtration  from  the  bacteriological  point  of  view  has  led 
to  most  important  discoveries,  we  must  accept  it  as  our 
safest  guide. 

Professor  P.  Frankland  in  1885  commenced  a  series  of 
bacteriological  experiments  bearing  on  the  filtration  of 
water  at  the  London  Waterworks,  which  led  him  to 
conclude  that  to  obtain  satisfactory  results — (1)  The  storage 
of  the  unfiltered  water  should  be  considerable,  to  allow  of 
sedimentation;  (2)  The  filtration  should  not  exceed  a 
certain  rate;  (3)  The  depth  of  fine  sand  should  be  con- 
siderable; and  (4)  The  filtering  materials  should  be 
renewed  frequently.  The  effect  of  subsidence  in  diminish- 
ing the  number  of  bacteria  in  water,  and,  therefore,  in 
diminishing  the  risk  of  disseminating  disease,  is  well  shown 
in  the  following  table,  taken  from  a  paper  by  Professor 
Frankland,  read  at  the  Edinburgh  Congress  of  Hygiene 
(1893). 

TABLE  SHOWING  THE  BACTERIAL  EFFECT  OF  SUBSIDENCE  IN 
THE  RESERVOIRS  OF  THE  WEST  MIDDLESEX  NEW  RIVER 
COMPANIES  :  — 

No.  of  Micro- 
organisms in 
1  c.c.  of  Water. 

New  River  Company  at  Stoke  Newington — 

Cutting  above  reservoir 677 

After  passing  through  first  reservoir         .         .        560 
After  passing  through  second  reservoir    .         .         183 


256  WATER  SUPPLIES 

West  Middlesex  Company  at  Barnes — 

Thames  water  as  abstracted  at  Hampton  .  1437 

After  passing  through  first  reservoir         .  .  318 

After  passing  through  second  reservoir    .  .  177 

By  far  the  most  important  and  extended  series  of  obser- 
vations on  the  purification  of  water  by  sand  nitration  has 
been  conducted  by  the  Massachusetts  State  Board  of 
Health,  and  published  in  their  Annual  Reports  (1890-93). 
In  1891,  investigations  at  the  experiment  station  having 
confirmed  the  belief  that  the  typhoid  bacillus  was  some- 
times present  in  sewage-polluted  waters,  and  was  able 
to  live  therein  for  at  least  three  weeks,  and  further 
investigations  by  the  Board  having  proved  that  high  death- 
rates  from  typhoid  fever  result  from  the  drinking  of  such 
water,  a  special  study  was  made  "  of  filtering  materials 
coarse  enough  to  purify  a  municipal  water  supply  economi- 
cally, while  removing  these  disease-producing  germs/'  It 
was  proved  by  these  experiments  that  water  could  be 
filtered  at  the  rate  of  2,000,000  gallons  per  acre  daily, 
"  with  the  removal  of  substantially  all  the  disease-producing 
germs  which  may  be  present  in  the  unfiltered  water."  The 
experiments  were  made  with  water  to  which  approximately 
known  numbers  of  the  B.  prodigiosus  or  B.  typhi  abdomi- 
nalis  had  been  added.  The  former  bacillus  was  usually 
selected  on  account  of  the  similarity  of  its  life  history  to 
that  of  the  typhoid  bacillus,  and  because  the  results 
obtained  with  it  were  more  reliable.  The  number  of 
bacilli  added  varied  from  a  small  number  to  several 
hundred  thousands  per  cubic  centimetre.  The  following 
table,  from  the  Report  for  1892,  "  shows  the  average 
percentages  removed  of  single  species  of  bacteria  under 
favourable  conditions,  and  by  filters  which  can  be  con- 
structed on  a  large  scale." 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        25? 


No.  of 
Filter. 

Rate—  Gallons  per 
Acre  Daily. 

Kind  of  Bacteria. 

Per  Cent. 
Removed. 

36  A 

1,500,000 

B.  typhi  abdominalis 

99-93 

36  A 

3,000,000 

B.  prodigiosus 

99-95 

33  A 

2,000,000 

Do. 

99-96 

34  A 

2,000,000 

Do. 

99-98 

37 

2,000,000 

Do. 

99-89 

Filter  36  A  consisted  of  58  inches  of  sand  of  an  effective 
size  of  .20  millimetre,  with  a  loam  layer  1  inch  deep  placed 
1  foot  below  the  surface. 

Filter  33  A  consisted  of  60  inches  of  sand  of  an  effective 
size  of  .14  millimetre. 

Filter  34  A  consisted  of  60  inches  of  sand  of  an  effective 
size  of  .09  millimetre. 

Filter  37  consisted  of  61  inches  of  sand  of  an  effective 
size  of  .20  millimetre. 

Such  a  high  degree  of  efficiency  had  not  before  been 
obtained,  and  if  such  results  are  obtainable  on  a  large 
scale,  the  danger  to  be  apprehended  from  the  use  of  sewage- 
polluted  waters  which  have  been  so  carefully  filtered  would 
seem  to  have  been  reduced  to  a  minimum.  The  filtration 
at  the  Altona  Waterworks,  which  Koch  believes  practically 
saved  the  city  from  an  outbreak  of  cholera,  was  certainly 
not  nearly  so  thorough,  and  the  same  applies  to  the 
filtration  of  the  Thames  water  as  supplied  to  London, 
which  for  so  long  has  secured  the  inhabitants  immunity 
from  typhoid  epidemics. 

The  filtering  materials  experimented  with  were  placed 
in  galvanised  iron  tanks  about  6  feet  deep  and  20  inches 
in  diameter,  and  the  rapidity  of  filtration  was  regulated 
by  a  tap  at  the  bottom.  Beneath  the  effective  sand  was 
a  layer,  1J  inches  thick,  of  coarse  sand,  and  below  this 
successive  layers  of  gravel,  increasing  in  size,  the  whole 
having  only  a  depth  of  3J  inches.  It  was  found  best  to 
pack  the  sand  dry,  as,  when  introduced  with  water, 


258  WATER  SUPPLIES 

stratification  took  place.  The  polluted  water  was  supplied 
continuously  from  a  small  reservoir,  the  excess  passing  off 
through  an  overflow,  so  that  the  depth  of  water  upon  the 
filter  bed  remained  constant,  throughout  the  experiments. 
When  the  accumulation  of  suspended  matter  on  the  surface 
of  the  filter  bed  impeded  the  filtration  to  such  an  extent 
that  the  tap  at  the  bottom  when  wide  open  did  not  pass 
the  water  at  the  prescribed  rate,  the  upper  surface  of  the 
sand  was  removed.  The  sand  used  was  carefully  sifted, 
and  its  "  effective  size  "  determined  by  further  sifting  a 
sample.  This  size  is  such  that  10  per  cent,  of  the  sand  is 
of  smaller  grains,  as  ascertained  by  sifting,  whilst  the 
remainder  is  of  larger  grains.  The  results  of  the 
Massachusetts  experiments  may  be  briefly  summarised  as 
follows  :  — 

(a)  Increased  rapidity  of  filtration  with  deep  layers  of 
sand  caused  a  slightly  larger  proportion  of  the  bacteria  to 
pass   through   the   filter.     With   thinner   layers   still   more 
bacteria  were  able  to  pass. 

(b)  With    both    continuous    and    intermittent    filtration 
the  finer  sands  are  slightly  more  effective  than  the  coarser 
ones. 

(c)  The  depth  of  sand  within  certain  limits  exerted  but 
little  influence  except  when  the  water  was  being  filtered 
rapidly;    with   moderate   rapidity   of   filtration    (2,000,000 
gallons  per  acre  daily)   1   foot  of  sand  appeared  to  be  as 
effective    as    5    feet. 

(cT)  In  filters  made  of  coarse  sand,  the  addition  of  a  loam 
layer  increased  the  efficiency.  When  the  effective  size  did 
'  not  exceed  .20  millimetre  and  the  filtration  was  not  too 
rapid,  the  loam  had  little  or  no  influence. 

(e)  The  effect  of  scraping  the  sand  to  remove  the  clogged 
surface  was  to  cause  an  increased  number  of  organisms  to 
pass  through  the  filter.  The  filters  required  three  days' 
use  after  scraping  usually  to  reach  their  maximum  degree 
of  efficiency.  The  effect  of  scraping  was  more  marked  in 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        2$g 

shallow  than  in  deep  niters,  and  with  high  rates  than  with 
low  rates  of  filtration. 

(/*)  Over  80  per  cent,  of  the  bacteria  removed  were  found 
in  the  upper  inch  of  sand,  and  55  per  cent,  in  the  upper 
quarter-inch.  The  B.  prodigiosus,  which  is  very  like  the 
•typhoid  bacillus  in  its  mode  of  life  in  water,  was  not  found 
below  the  upper  inch. 

(g)  The  average  depth  of  sand  necessary  to  be  scraped 
from  the  surface  of  the  filter  was  a  quarter  of  an  inch,  but 
was  found  to  vary  with  the  size  of  the  sand,  decreasing  as 
the  fineness  of  the  sand  increased. 

(h)  Much  less  water  will  pass  a  filter  at  32°  F.  than  at 
70°  F.,  owing  to  the  increased  viscosity  of  the  water. 

(i)  Within  certain  limits  and  under  equal  conditions  the 
quantity  of  water  passed  between  successive  scrapings  is 
not  influenced  by  the  rate  of  filtration. 

(j)  Finer  sands  require  more  frequent  scraping  than 
coarser  sands,  whether  the  filtration  be  continuous  or 
intermittent. 

(k)  Shallow  filters  require  more  frequent  scraping  than 
the  deeper  ones.  This  appears  to  be  entirely  due  to  the 
greater  head  available  in  the  deeper  filters  for  overcoming 
friction. 

(1)  Filters  used  continuously  require  less  frequent  scrap- 
ing than  when  used  intermittently. 

The  bacteriological  examination  of  the  effluents  from  all 
the  filters  in  July  and  August  showed  that  a  larger  number 
of  organisms  were  then  present  than  at  any  other  time. 
From  the  results  of  the  experiments  which  were  instituted 
to  ascertain  the  cause,  the  reporters  infer :  — 

1.  That  during  the  summer  months  the  temperature  or 
other  conditions  for  continuation  of  life  of  bacteria  at  the 
surface  of  filters  are  more  favourable  than,  at  any  other 
time. 

2.  That    certain    species    of    bacteria    are    even    able    to 


260  WATER  SUPPLIES 

multiply  there  at  times  during  this  period,  although  most 
species  rapidly   decline. 

3.  That  this  is  far  less  noticeable  in  the  case  of  inter- 
mittent than  of  continuous  filters. 

4.  That   typhoid-fever  germs   fail   to   grow   under   these 
conditions,  so  that  the  hygienic  value  of  nitration  is  not 
affected  by  the  growth  during  warm  weather  of  a  very  few 
species  of  the  more  hardy  water-bacteria. 

The  above  results  have  been  confirmed  in  important 
particulars  by  Dr.  Koch,  but  he  has  also  shown  that  some 
of  their  conclusions  must  be  received  with  caution.  The 
conclusions  at  which  he  has  arrived  from  the  study  of  the 
outbreak  of  cholera  at  Altona,  and  of  other  epidemics  due 
to  imperfectly-filtered  water,  are — (1)  That  the  real  effec- 
tive agent  in  removing  micro-organisms  from  the  water 
being  filtered  is  the  layer  of  slimy  organic  matter  which 
forms  upon  the  surface  of  the  sand.  (2)  That  if  this  surface 
be  removed  by  scraping,  or  its  continuity  affected  in  any 
way,  as  by  the  freezing  of  the  surface,  the  number  of 
bacteria  which  pass  through  the  filtering  material  increases 
considerably ;  in  fact,  both  cholera  and  typhoid  germs  may 
pass  in  sufficient  numbers  to  cause  an  epidemic  amongst 
'those  who  use  the  imperfectly-filtered  water.  (3)  That 
water  should  not  pass  through  the  filters  at  a  rate 
exceeding  100  mm.  per  hour  (about  2,000,000  gallons  per 
acre  daily).  (4)  That  after  a  filter  bed  has  been  scraped, 
water  should  be  allowed  to  stand  upon  it  for  at  least 
twenty-four  hours,  to  allow  of  the  slime  depositing  before 
filtration  is  commenced,  and  that  the  water  which  first 
passes  through  should  not  be  allowed  to  reach  the  pure- 
water  reservoir. 

At  the  Altona  Waterworks  the  filtered  water  has  been 
regularly  examined  bacteriologically  since  the  summer  of 
1890.  .By  keeping  the  pace  of  filtration  below  2,000,000 
gallons  per  acre  daily,  the  bacteria  in  each  c.c.  of  the 
filtered  water  practically  always  remained  below  100; 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        261 

usually  they  were  much  below — 20  to  30  being  the  average. 
In  January,  1892,  the  number  of  micro-organisms  suddenly 
increased  to  from  1,000  to  2,000  per  c.c.,  and  in  February 
an  outbreak  of  typhoid  fever  occurred.  Suspicion  was 
expressed  that  nitration  might  have  been  disturbed  by  ice 
formation,  or  by  the  superficial  layers  of  sand  becoming 
frozen  during  the  process  of  cleansing  in  the  keen  frosty 
weather;  but  absolute  proof  was  not  forthcoming.  In 
January  and  February,  1893,  the  epidemic  of  cholera 
occurred  in  the  town,  and  this  had  been  preceded  by  an 
increase  in  the  number  of  bacteria  in  the  filtered  water. 
On  the  30th  December,  1892,  the  number  of  germs  began 
to  increase,  and  reached  on  the  12th  January,  1893,  the 
number  of  1,516,  and  remained  high  until  early  in 
February.  Up  to  this  time  the  water  from  each  filter  bed, 
of  which  there  were  ten,  had  not  been  examined  separately ; 
when  so  examined,  from  the  1st  of  February  Filter  No.  8 
was  found  to  be  acting  worst.  On  the  3rd  this  filter  was 
examined,  and  when  the  water  was  drawn  off  it  was  found 
that  the  sand  layer  was  frozen  at  the  top.  The  freezing 
had  taken  place  during  the  period  of  cleansing. 

Koch  also  points  out  that  winter  with  its  period  of 
frost  is  not  the  only  enemy  of  filtration.  Occasionally  in 
summer,  river  and  stored  surface-water  is  so  rich  in  vege- 
table growths  that  these  rapidly  form  an  almost  impervious 
layer  upon  the  surface  of  the  sand,  and  to  keep  up  the 
supply  of  filtered  water,  greater  pressure  and  more  frequent 
cleansing  are  necessary,  both  tending  to  give  a  filtered 
water  which  is  imperfectly  purified.  These  disturbances, 
however,  are  only  dangerous  to  the  public  health  when  the 
natural  water  contains  specific  bacteria,  and  as  the  whole 
filters  are  never  affected  at  the  same  time  only  a  portion  of 
the  disease  germs  could  ever  pass.  Yet  that  even  this 
part  can  cause  epidemic  outbreaks  is  proved  by  the  experi- 
ence of  Altona,  Berlin,  and  other  places.  To  secure 
efficient  filtration  Koch  lays  down  the  following  rules :  — 


262  WATER  SUPPLIES 

1.  The  pace  of  filtration  must  not  exceed  100  mm.  in  the 
hour.     To  make  sure  of  this  each  separate  filter  must  be 
provided  with   a   contrivance   by  which   the   movement   of 
the  water  in  the  filter  can  be  restricted  to>  a  certain  pace, 
and  continually  regulated  so  as  to  keep  that  pace. 

2.  Each  separate  filtering  basin  must,  when  in  use,  be 
bacteriologically  investigated  once  each  day.     There  should, 
therefore,  be  a  contrivance  enabling  samples  of  water   to 
be  taken  immediately  after  they  have  passed  the  filter. 

3.  Filtered  water  containing  more  than  100  germs, 
capable  of  development,  in  a  cubic  centimetre  should  not 
be  allowed  to  reach  the  pure-water  reservoir.  The  filter 
should,  therefore,  be  so  constructed  that  insufficiently  pure 
water  can  be  removed  without  its  mixing  with  the  good 
filtered  water. 

4.  The  filter  beds  should  be  of  small  area,  far  smaller 
than  those  used  in  London,*  or  recently  constructed  at 
Hamburg. 

At  the  same  time  Koch  admits  that  in  waterworks  of 
good  construction  and  intelligent  management,  Rule  2 
need  only  be  strictly  observed  in  times  of  danger.  He  is 
also  bound  to  admit  that  the  standard  of  100  germs  per  c.c. 
is  arbitrary,  and  is  only  "  intended  to  give  a  basis  obtained 
from  experience  to  form  a  proper  judgment."  There  are 
strong  grounds  for  suspecting  that  at  Altona  a  number  of 
cases  of  cholera  occurred,  though  not  an  epidemic  outbreak, 
during  the  period  when  the  filtration  was  up  to  Koch's 
standard,  and  that  these  were  due  to  the  water  being 
specifically  infected.  As  the  typhoid  bacillus  is  much 
smaller  than  the  cholera  germ,  it  would  seem  probable 
that  the  danger  of  disseminating  typhoid  fever  by  the 
distribution  of  imperfectly-filtered  water  is  greater  than  in 
the  case  of  cholera. 

Prior  to  the   investigations  of  the  Massachusetts   State 

*  The  average  size  of  these  is  one  acre. 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        263 

Board  of  Health,  the  small  amount  of  chemical  purification 
produced  by  sand  filtration  was  attributed  to  the  oxidation 
of  the  organic  matter  by  the  oxygen  held  in  the  pores  of 
the  sand.  By  the  experiments  above  referred  to  the 
oxidation  was  proved  to  be  due  to  the  action  of  nitrifying 
organisms,  which  adhere  to  the  sand.  When  nitrification 
has  been  well  established  in  a  filter,  the  rate  of  filtration 
within  certain  limits  was  found  to  exert  but  little  influence 
upon  the  removal  of  the  organic  matter.  Also,  within 
certain  limits,  the  effect  varied  little  with  the  degree  of 
coarseness  of  the  sand,  but  deeper  filters  were  more  efficient 
in  removing  the  organic  matter  than  shallower  ones.  In 
some  experiments  with  filters  in  which  the  nitrifying 
action  had  become  well  marked,  the  albuminoid  ammonia 
yielded  by  the  effluent  was  80  per  cent,  less  than  that 
yielded  by  the  water  before  filtration.  The  importance  of 
removing  as  much  as  possible  of  the  organic  matter  is  due 
to  the  fact  that  the  food  supply  available  for  the  bacteria 
which  are  present  is  reduced  thereby,  and  their  growth  and 
multiplication  in  the  water  subsequently  is  retarded. 

Experiments  which  were  mad©  with  the  coloured  water 
of  the  Merrimac  River  proved  that  new  sand  removed  the 
colour  more  efficiently  than  sand  which  had  been  in  use 
some  time.  One  filter  of  sand  and  loam  continued  to 
remove  all  the  colour  for  over  two  years;  after  the  end  of 
the  third  year  the  water  which  passed  through  was  very 
slightly  but  uniformly  coloured. 

The  oxidising  effects  produced  by  sand  filtration  are, 
however,  in  the  light  of  recent  bacteriological  research, 
of  very  secondary  importance  in  the  purification  of  water. 
Any  considerable  chemical  purification  cannot  be  con- 
stantly relied  upon  when  water  is  treated  on  a  large  scale. 
New  sand  filters  have  but  little  action.  It  is  only  when 
they  have,  so  to  speak,  become  charged  with  the  nitrifying 
organisms  that  any  appreciable  effect  is  produced,  and  it 
takes  some  time  for  this  action  to  become  well  established. 


264  WATER  SUPPLIES 

Moreover,  the  nitrification,  after  proceeding  satisfactorily 
for  a  time,  may  suddenly  cease,  to  commence  again  after  a 
more  or  less  lengthy  interval.  The  cause  of  this  inter- 
mittent action  is  difficult  to  explain.  The  Massachusetts 
investigators  think  that  the  action  probably  only  com- 
mences when  a  certain  quantity  of  nitrogenous  matter  has 
become  stored  up  in  the  pores  of  the  sand.  It  then 
proceeds  rapidly  until  this  is  consumed,  and  again  ceases 
until  a  further  quantity  has  accumulated,  and  this  may 
require  months.  Another  singular  fact  is  that  the  total 
nitrogen  in  the  unfiltered  water  almost  invariably  exceeds 
that  found  in  the  filtrate,  which  appears  to  indicate  that 
some  of  the  nitrogen  is  liberated  in  the  gaseous  state  and 
escapes  into  the  air. 

The  filter  beds  of  the  eight  London  Water  Companies 
exceed  100  acres  in  area.  The  depth  of  sand  used  by  the 
various  Companies  varies  f rom  2  feet  to  4  feet  6  inches, 
and  the  depth  of  the  filter  beds  from  2  feet  9  inches  to 
8  feet.  The  following  description  of  the  Leeds  Waterworks 
may  be  cited  as  an  example  of  the  most  modern  system  of 
sand  filtration.  The  water  from  the  Washburn  valley  and 
moorlands  is  collected  in  a  reservoir  195  acres  in  extent, 
and  capable  of  holding  a  year's  supply.  From  this  it 
passes  to  a  settling  pond,  having  an  area  of  3  acres-,  and 
capable  of  holding  10,000,000  gallons.  A  certain  amount 
of  water,  however,  is  collected,  which  flows  directly  into 
this  settling  reservoir.  From,  here  it  flows  on  to  the  filter 
beds,  seven  in  number,  each  having  an  area  of  nearly  an 
acre.  The  filter  beds  consist  of  2  feet  of  fine  sand,  3  inches 
of  pea-gravel,  3  inches  of  J-inch  gravel,  4  inches  of  1-inch 
gravel,  and  9  inches  of  rough  stones.  The  water,  after 
passing  through  the  beds,  enters  a  series  of  perforated 
pipes  3  and  4  inches  in  diameter,  all  of  which  discharge 
into  a  main  culvert  along  the  centre,  terminating  in  a 
small  circular,  covered  tank,  where  observations  can  be 
made  as  to  the  rate  at  which  the  water  is  passing  through 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        265 

the  bed.  The  filtered  water  is  then  conducted  into  a 
service  reservoir.  In  the  middle  of  each  bed  is  a  rectangular 
iron  box,  used  for  washing  the  sand  scraped  from  the 
surface  of  the  filter  during  the  process  of  cleansing.  The 
filters  are  cleaned  in  order,  one  each  week  on  an  average, 
from  J  to  §  of  an  inch  of  the  surface  being  removed.  This 
is  wheeled  along  planks  to  the  washing  box,  and  after  being 
washed  is  again  replaced.  When  the  tanks  are  emptied  for 
cleansing,  the  water  is  only  drawn  off  to  near  the  bottom 
of  the  sand,  and  in  refilling  the  water  is  backed  up  from 
below,  and  not  discharged  on  to  the  surface,  as  this  would 
disturb  it  and  impair  the  efficiency  of  the  filtration;  The 
air  in  the  sand  escapes  not  only  from  the  surface,  but  also 
from  escape  pipes,  which  pass  through  the  walls  of  the 
tanks.  If  this  precaution  be  not  taken  the  air  may  cause 
fissures  to  form  in  the  sand.  When  the  water  has  risen 
above  the  surface  of  the  sand  it  is  then  turned  on  from 
above,  and  flows  over  the  side  of  a  trough,  so  as  to  be 
uniformly  supplied  to  the  filter  with  the  minimum  amount 
of  disturbance.  Eight  men  are  constantly  employed  in 
keeping  the  filters  in  thorough  working  order.  On  an 
average  each  square  yard  of  filter  passes  412.  gallons  of 
water  per  twenty-four  hours.  The  head  of  water,  or  rather 
the  difference  in  level  between  the  surface  of  the  water  on 
the  filter  and  in  the  circular  tank  into  which  the  filtered 
water  is  discharged  4  to  4J  feet. 

Table  VIII.  gives  the  area  in  acres,  rapidity  of  filtration, 
etc.,  of  the  filter  beds  of  several  large  public  supplies, 
compiled  from  a  report  of  a  sub-committee  of  the  Dumfries 
Town  Council,  which  considered  the  subject  with  the  view 
of  improving  their  filtering  arrangements.  The  River 
Commissioners  on  Metropolitan  Water  Supply  reported 
that,  as  a  general  rule,  the  filtration  of  water  by  the 
London  Companies  was  carried  out  efficiently,  from  98  to 
99  per  cent,  of  the  organisms  being  removed  from  the 
water.  The  occasional  failures,  they  thought,  could  be 


266 


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PURIFICATION  OF  WATER  ON  LARGE  SCALE        267 

reniedied  by  increasing  the  number  of  filter  beds  or  by 
having  recourse  to  double  nitration ;  "  and  assuming  the 
water  to  be  invariably  as  efficiently  treated  as  it  is  usually 
by  the  most  careful  of  the  Companies,  the  raw  waters  of 
the  Thames  and  Lea  can  be  transformed,  in  the  judgment 
of  Prof.  P.  Frankland, — who',  as  is  well  known,  has  been  no 
sparing  critic  of  the  London  water, — into  a  beverage  quite 
as  good,  from  the  point  of  view  of  health,  as  deep-well 
water."  This  opinion,  it  must  be  remembered,  is  not 
shared  by  many  other  sanitarians  of  equal  eminence.  In 
any  case  it  is  obvious  that  only  the  efficiency  of  the 
filtration  can  safeguard  the  metropolis  from  outbreaks  of 
typhoid  fever  and  possibly  of  cholera.  Doubtless,  however, 
the  Water  Companies  will  not  be  slow  to  adopt  the 
recommendation  of  the  Commissioners,  and  will  take  every 
precaution  suggested  by  the  breakdown  of  the  filtering 
arrangements  at  Altona. 

The   area  of  filtering  surface   required  is  given  by   the 

formula  A  =  —  where  Q  is  the  maximum  daily  demand  in 
-t' 

cubic  feet,  F  the  filtering  rate  in  feet,  and  A  the  required 
area  in  square  feet.  This  area  must  always  be  available; 
hence  a-n  additional  area  must  be  provided  for  use  whilst 
other  portions  are  being  cleansed.  According  to  Hennel 
the  number  of  filter  beds  required  for  different  populations 
is  as  under  :  — 

Population.  No.  of  Filter  Beds. 

2,000  ......  2 

10,000  .         .         .         .         .         .  3 

60,000  .         .         .         /-•    ...  4 

200,000  ......  6 

400,000 8 

600,000 12 

1,000,000 16 

These  include  filter  beds  out  of  use  for  cleansing. 

In  all  cases  a  sufficient  number  of  filter  beds  should  be 


268  WATER  SUPPLIES 

provided,  to  allow  of  the  cleansing  and  renovating  of  one 
set  without  overworking  the  remainder.  The  filtration 
must  not  be  too  rapid,  not  over  2,000,000  gallons  per  acre 
daily.  To  accomplish  this  the  head  of  water  must  be 
reduced  after  cleansing,  and  gradually  increased  as  the 
pores  of  the  sand  become  closed  by  the  slimy  matter  which 
settles  on  its  surface.  By  "  filtering  head  "  is  meant  the 
difference  between  the  level  of  the  water  on  the  bed  and 
in  the  well  which  receives  the  filtered  water.  After 
cleansing  a  few  inches  of  head  may  be  sufficient ;  when  it 
exceeds  3  feet  the  surface  again  requires  renewal.  Each 
bed  should  have  an  arrangement  for  regulating  the  flow, 
and  the  water  should  be  admitted  into  the  filter  beds  in 
such  a  manner  as  not  to  disturb  the  surface.  The  surface 
sand  when  removed  for  cleansing  may  be  washed  in  hoppers 
admitting  the  water  from  below,  or  in  troughs  through 
which  water  is  constantly  flowing.  Deep  filter  beds, 
keep  the  water  cooler  in  summer  and  retard  freezing  in 
winter,  the  latter  being  the  more  important,  since  freezing 
not  only  interferes  with  the  efficiency  of  the  filtration,  but 
may  damage  the  walls  of  the  filter  beds,  by  the  expansion 
of  the  surface  water  in  the  act  of  freezing. 

In  many  places  water  is  obtained  from  galleries  or 
trenches  sunk  along  the  edge  of  lakes  or  running  streams, 
the  general  impression  being  that  the  water  so  obtained  is 
derived  from  the  lake  or  stream,  and  that  it  undergoes  a 
process  of  natural  purification  and  filtration  in  its  passage 
through  the  intervening  soil.  In  many  cases,  however, 
this  is  really  ground  water  which  is  intercepted  on  its  way 
to  its  natural  outlet.  Such  water  is  usually  very  free 
from  organic  matter,  and  contains  but  few  bacteria. 
Where  the  ground  water  falls  below  the  level  of  the  water 
in  the  stream  or  lake,  doubtless  a  certain  quantity  of  the 
water  which  passes  into  the  galleries  is  derived  from  the 
latter  sources,  and  is  not  so  likely  to  be  of  good  quality,  since 
jt  only  passes  through  soil  which  is  constantly  saturated 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        269 
\ 

with  water,  and  therefore  never  aerated,  and  destitute  of 
any  oxidising  powers.  In  such  cases  also  the  nitration  is 
liable  to  be  inefficient,  and  to  allow  of  bacteria  and  other 
participate  matters  passing  into  the  collecting  channels. 

Many  attempts  have  been  made  to  filter  water  on  the 
large  scale  without  employing  filter  beds,  which  are  ex- 
pensive not  only  on  account  of  the  space  required,  but  of 
the  constant  labour  and  attention  required  to  keep  them  in 
a  state  of  efficiency.  One  of  the  best-known  processes  is 
that  of  the  Atkins  Filter  and  Engineering  Company, 
which  is  in  use  by  the  Henley-on-Thames  Water  Company, 
and  has  been  adopted  by  many  large  institutions.  The 
filtering  apparatus,  technically  known  as  the  "  Scrubber/' 
consists  of  a  perforated  metal  cylinder  to  contain  the  sand 
or  other  filtering  material,  fitted  into  a  tank  and  so 
arranged  as  to  revolve  easily  by  turning  a  handle.  The 
cylinder  is  only  partly  filled  with  the  filtering  material, 
and  the  collecting  tubes,  which  convey  away  the  filtered 
water,  lie  as  nearly  as  possible  in  the  centre  of  this  as  it 
lies  in  the  cylinder.  To  clean  the  filter  it  is  only  necessary 
to  turn  the  handle,  when  the  cylinder  revolves,  agitating 
the  filtering  material  with  the  water,  and  the  latter, 
together  with  the  impurities  washed  out,  are  run  off 
through  a  by-pass.  Several  such  "  scrubbers "  can  be 
connected  together.  By  another  arrangement  the  sand  is 
put  into  a  number  of  discs  fitted  on  a  revolving  centre 
collecting-tube.  The  water  filters  through  the  flat  surface 
of  each  disc,  so  that  the  area  of  filtering  surface  is  much 
increased.  More  perfect  filtration  can  be  secured  by  passing 
the  water  through  two  "  scrubbers "  in  succession,  and 
affords,  naturally,  safef  results  for  drinking  water.  The 
Company  claims  that,  with  an  area  of  only  600  square  feet, 
their  machines  will  filter  as  much  water  as  an  acre  of  filter 
bed  (3,000,000  gallons  per  day).  Under  the  latter  system 
the  cost  of  cleansing  is  said  to  be  from  5s.  to  10s.  per 
million  gallons,  whereas  it  is  only  about  half  the  amount 


ayo  WATER  SUPPLIES 

with  the  Atkiii  "scrubbers/'  with  "the  great  sanitary 
improvement  of  daily  cleansing  in  addition."  Such 
machines  for  rapid  nitration  do  not  appear  to  be  regarded 
with  much  favour  in  this  country,  and  there  are  no  records 
of  the  bacteriological  examination  of  waters  which  have 
passed  through  these  filters.  The  conditions  laid  down  by 
the  Massachusetts  Board  as  being  necessary  for  perfect 
filtration  not  being  observed,  experimental  evidence  of 
efficiency  is  much  to  be  desired.  Other  machines  of  a 
similar  character — the  "  Loomis,"  the  "  Duplex,"  the 
"  Hyatt,"  the  "  Bowden,"  etc. — are,  however,  in  use  in 
the  United  States,  chiefly  for  filtering  turbid  river-water. 
A  commission  appointed  by  the  city  of  Pittsburg  has 
recently  (1899)  presented  a  report  containing  the  results  of 
a  number  of  experiments  comparing  the  efficiency  of  sand 
and  mechanical  filters  when  used  for  the  river  water 
supplying  the  city.  They  found  that  the  use  of  a  coagulant 
was  necessary  in  both  systems,  but  preference  was  given  to 
sand  filtration.  The  report  states :  "  With  an  amount  of 
sulphate  of  alumina  which  makes  the  cost  of  the  two 
processes  substantially  equal  the  mechanical  filters  yield 
effluents  containing  from  two  to  three  times  as  many 
bacteria  as  the  sand  filters."  Dr.  P.  S.  Wales,  Medical 
Director,  United  States  Navy,  states  that,  with  these 
mechanical  filters,  98  per  cent,  of  the  micro-organisms  can 
be  removed,  but  that  spores  readily  pass  through  the 
filtering  material.  (The  typhoid  and  cholera  bacilli  are 
not  known  to  form  spores.)  The  four  machines  above 
referred  to  have  been  used  for  experimental  purposes  at 
the  Museum  of  Hygiene,  Washington,  D.C.,  and  gave  very 
satisfactory  results.  The  system  of  rapid  filtration  is 
pursueid,  amongst  other  places,  at — 

Oakland,  Gal.,  capacity  for  24  hours  .  4,000,000  gallons 

Atlanta,  Ga.  „  „  .  3,000,000      „ 

Long  Branch,  N.Y.        „  „  .  2,000,000      „ 

Ottumwa,  Iowa  „  ,,  .  1,500,000      „ 

Athol,  Mass.  „  „  .  1,000,000      „ 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        271 

The  city  of  Alleghany,  Pa.,  was  contemplating  erecting 
a  plant  for  filtering  30,000,000  gallons  per  day,  when  Dr. 
Wales's  paper  was  published.*  These  filters  appear  to  be 
especially  applicable  for  the  waters  of  muddy,  rapid  rivers, 
which  speedily  clog  the  ordinary  sand  filter,  and  arrest  the 
flow  of  water.  To  expedite  the  process  of  sedimentation 
so  as  to  remove  more  of  the  suspended  matter  before 
passing  the  water  into  the  filters,  alum  is  largely  used. 
Tjhe  addition  of  about  half  a  grain  per  gallon,  on  the 
average,  is  sufficient.  At  the  Atlanta  Waterworks,  during 
1890,  253  Ib.  of  alum  were  used  per  day,  corresponding  to 
617  grains  per  1,000  gallons.  Some  waters,  such  as  that 
of  the  Potomac,  cannot  be  clarified  without  a  coagulant. 
Ferrous  sulphate  has  been  used  in  some  cases  instead  of 
alum,  and  with  advantage.  In  this  country  the  water 
supply  to  the  village  of  Ingatestone  (Essex),  previously 
referred  to,  derived  from  a  fine,  sandy  clay,  for  years 
resisted  all  our  efforts  to  clarify  it.  Alum,  or  rather 
Spence's  Aluminoferric,  was  used  as  a  coagulant,  and  the 
water  then  filtered  through  vertical  sheets  of  flannel.  This 
not  proving  satisfactory,  various  recently-introduced  filter- 
ing and  purifying  materials  were  experimented  with. 
Finally,  at  my  recommendation,  a  filter  bed  was  made  of 
sand  and  polarite  mixed  in  equal  proportions,  and  with  a 
few  inches  of  fine  sand  on  the  top.  This  filter  for  several 
years  answered  admirably,  and  the  use  of  the  alum  was 
discontinued.  Two  beds  were  prepared,  so  that  one  could 
be  used  whilst  the  other  was  cleansed  and  allowed  to  rest 
for  re-aeration.  A  fresh  source  of  supply  is  now  being 
sought. 

At  the  Antwerp  Waterworks,  "  spongy  iron,"  together 
with  gravel,  was  used  as  filtering  material,  but  the  beds 
choked  up  gradually  and  the  iron  became  almost  inactive. 


*  Transactions  of  International  Congress  of  Hygiene,  London,  1891, 
vol.  vii. 


272  WATER  SUPPLIES 

For  three  years,  however,  the  results  were  satisfactory,  so 
far  as  regards  the  purification  of  the  water.  To  meet  the 
difficulties  just  referred  to,  Dr.  W.  Anderson,  F.R.S., 
invented  the  "  Revolving  Purifier,"  which  has  been  in  use  at 
Antwerp  since  1885,  and  has  also  been  adopted  at  Boulogne- 
sur-Seine,  Agra,  Monte  Video,  and  other  places.  The 
apparatus  is  described  by  the  inventor  as  a  "  cylinder 
supported  horizontally  on  two  hollow  trunnions,  of  which 
one  serves  for  the  entrance  and  the  other  for  the  exit  of 
the  water.  The  cylinder  contains  a  certain  quantity  of 
metallic  iron,  in  the  form  either  of  cast-iron  borings,  or, 
preferably,  of  scrap  iron,  such  as  punchings  from  boiler 
plates.  The  cylinder  is  kept  in  continuous  but  slow 
rotation  by  any  suitable  means,  the  iron  being  continually 
lifted  up  and  showered  down  through  the  passing  water 
by  a  series  of  shelves  or  scoops  fixed  inside  the  shell  of  the 
cylinder.  By  this  means  the  water,  as  it  flows  through, 
is  brought  thoroughly  into  contact  with  the  charge  of  iron, 
which,  in  addition,  by  its  constant  motion  and  rubbing 
against  itself  and  the  sides  of  the  cylinder,  is  kept 
always  clean  and  active.  During  its  passage  through  the 
apparatus  the  water  takes  up  from  -^  to  1  of  a  grain 
of  iron  per  gallon,  which  is  got  rid  of  either  by  blowing  in 
air  or  by  allowing  it  to  flow  along  shallow  open  troughs. 
The  oxide  thus  formed  may  settle  in  subsidence  reservoirs, 
or  may  be  filtered  out  by  rapid  passage  through  a  thin  layer 
of  sand.  At  Boulogne  the  average  amount  of  organic 
matter  removed  by  this  process  from  the  Seine  water  was 
63  per  cent.,  and  the  microbes,  which  in  the  unfiltered 
water  ranged  from  800  to  over  7,000  per  cubic  centimetre, 
were  reduced  to  an  average  of  about  40.  The  bacterio- 
logical results  are  admittedly  only  approximate,  and  on 
one  occasion,  at  least,  a  large  number  of  bacteria  were 
found  in  the  filtrate.  It  seems  probable  that,  compared 
with  sand  filtration  as  usually  conducted,  the  revolving 
purifiers  may  destroy  a  larger  proportion  of  the  dissolved 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        273 

organic  matter;  but  unless  supplemented  by  careful  sand 
nitration  it  would  be  unsafe  to  assume  that  a  specifically- 
polluted  water  could  be  rendered  safe  for  drinking  purposes 
by  passing  through  one  of  these  cylinders. 

Whilst  sand  is  almost  universally  employed  for  the 
filtration  of  water  on  the  large  scale,  and  usually  is  the  sole 
effective  filtering  medium,  in  a  few  instances  other 
materials  have  been  used,  together  with  the  sand,  either 
mixed  therewith,  or  in  layers.  A  carbide  of  iron  (Spence's 
Magnetic  Carbide)  was  in  use  for  a  large  number  of  years 
for  filtering  the  excessively-polluted  Calder  water  for  the 
domestic  supply  to  Wakefield.  This  water  was  not  only 
fouled  by  sewage,  but  also  deeply  discoloured  by  the  refuse 
from  dye-works;  yet  the  filters  converted  it  into  a  colour- 
less, palatable  water.  The  layer  of  carbide  was  in  use  for 
nearly  thirty  years,  and  was  never  renewed ;  all  that  was 
found  to  be  required  was  the  cleansing  of  the  surface  sand. 
The  filtration  was  intermittent,  to  allow  of  the  aeration  of 
the  filter.  The  magnetic  carbide  is  also  in  use  at  Calcutta 
for  filtering  the  turbid  and  polluted  waters  of  the  Hooghly, 
and  at  Cape  Town,  Demerara,  and  other  places.  Its  use 
was  discontinued  at  Wakefield  because  a  purer  supply  has 
been  obtained  from  another  source.  Spongy  iron,  polar ite, 
and  other  insoluble  iron  compounds  are  used  for  similar 
purposes,  and  are  useful  in  special  cases,  as  in  the  examples 
given.  Now  that  the  removal  of  dissolved  organic  matter 
is  considered  to  be  of  much  less  practical  importance  than 
the  removal  of  the  living  organisms,  less  importance  is 
being  attached  to  the  use  of  such  materials,  and  it  can  only 
be  under  exceptional  conditions  that  these  aids  to  sand 
filtration  are  necessary.  It  is  upon  the  proper  use  of  sand 
that  the  real  efficiency  of  filtration  must  depend,  though 
where  desirable  this  may  be  supplemented  by  the  use  of 
other  filters,  or  the  introduction  of  a  layer  or  layers  of  other 
materials;  and  the  substances  above  enumerated,  yielding 
nothing  to  the  water,  yet  exerting  an  oxidising  action  upon 

18 


274  WATER  SUPPLIES 

the  organic  matter,  are  probably  the  best  which  have  yet 
been  discovered. 

At  Reading  Waterworks  polarite  is  now  largely  used 
for  filtering  the  water  of  the  Kennet,  a  polluted,  navigable 
stream.  The  following  description  of  the  filters  is  taken 
from  an  excellent  paper  read  by  Mr.  Walker  the  Water- 
works Engineer,  at  a  recent  meeting  of  the  County 
Association  of  Municipal  Engineers  held  in  Reading :  — 

"  The  process  of  purifying  the  river  Kennet  water  is  by 
natural  percolation,  through  a  series  of  filters  or  chambers, 
the  first  chamber  containing  coke,  and  the  second  and 
third  chambers  '  polarite/  granulated  in  two  sizes ;  there 
are  also  intermediate  or  regulating  water  chambers  for 
facilitating  cleaning  out,  the  water  passing  from  the  last 
polarite  chamber  into  a  distributing  channel,  and  on  to 
sand  filters,  as  it  has  been  said,  to  make  doubly  sure  of 
filtered  water ;  but  subsequent  experience  has  proved  that 
perfect  purification  can  be  obtained  by  polarite  chambers 
without  the  aid  of  sand.  The  first  two  sets  of  these 
chambers  were  started  in  work  in  November,  1892.  Each 
polarite  chamber  measures  40  feet  by  9  feet,  and  has  a 
depth  of  2 J  feet  of  polarite,  giving  an  area  of  40  yards  super 
each  chamber,  or  a  total  of  160  yards  super  for  the  two 
sets.  By  adding  the  2J  feet  of  polarite  in  each  set  it  gives 
a  depth  or  thickness  of  5  feet  to  each  set  of  chambers,  and 
an  area  of  80  yards  super  per  set.  From  December,  1892, 
to  August,  1893,  there  had  passed  through  these  two  sets 
a  total  quantity  of  409,880,000  gallons  of  water,  giving  an 
average  of  18,848  gallons  per  yard  super  per  day.  Two 
additional  sets  were  started  in  August  last,  1893,  of  the 
same  dimensions  as  the  above,  giving  a  total  area  of  160 
yards  super,  with  a  depth  of  5  feet  for  each  set  of  chambers, 
which  have  passed  on  an  average  12,500  gallons  per  yard  su- 
per per  day.  From  1st  January  of  the  present  year  (1894) 
to  the  31st  of  March  last,  190,218,319  gallons  of  water  have 
passed  through  these  chambers  giving  an  average  of 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        275 

13,215  gallons  per  yard  super  per  day,  or  at  the  rate  of 
550.6  gallons  per  yard  super  per  hour.  The  water  has  been 
such  that  no  complaints  (which  previously  were  an  every- 
day occurrence)  have  been  made  since  purification  by 
polarite  came  into  full  working  order.  It  has  had  a  most 
severe  test  during  the  past  and  previous  autumn  and 
winter  seasons,  but  like  many  a  good  engineer  it  has  often 
been  overworked,  but  has  stood  it  well.  From  experience 
gained  in  connection  with  the  treatment  of  the  river 
Kennet  water,  there  is  no  hesitation  in  stating  the  opinion 
that  '  polarite,'  as  applied  here,  is  capable  of  effectually 
purifying  a  river  water-supply  for  all  purposes,  and  the 
system  can  be  carried  out  at  less  cost  of  construction  and 
maintenance  than  filtration  by  large  areas  of  sand  beds." 

The  effluent  from  the  polarite  filters  is  afterwards  passed 
through  four  sand  filters,  each  having  an  area  of  10,000 
square  feet.  As  these  filters  pass  about  2,000,000  gallons 
per  day,  this  is  at  the  rate  of  over  8  gallons  per  square  foot 
per  hour,  or  four  times  the  average  of  the  London  Water 
Companies. 

An  addition  has  since  been  made  by  the  construction 
of  a  covered  filter-house,  having  four  sets  of  chambers 
capable  of  purifying  1,000,000  gallons  per  day.  This 
occupies  an  area  of  424  yards,  including  brickwork.  These 
chambers  were  set  to  work  in  June  1898,  and  have  given 
very  satisfactory  results.  It  is  now  9  years  since  polarite 
was  introduced  in  the  Reading  works,  and  Mr.  Walker's 
further  experience  has  confirmed  his  previous  report. 

In  connection  with  these  works  also  there  is  an  improved 
system  of  sand-washing,  which  was  invented  by  Mr.  Walker. 
Cone-shaped  hoppers,  mounted  on  trunnions,  and  connected 
at  the  bottom  of  the  inverted  cone  with  the  water  supply 
under  pressure,  are  filled  with  the  sand  scrapings  to  be 
washed.  The  water  is  then  turned  on,  and  the  upward 
rush  keeps  it  in  a  continuous  state  of  agitation,  and  the 
impurities  #re  carrieo!.  off  by  an  outlet  at  the  rim  of  the 


276  WATER  SUPPLIES 

hopper.  By  this  process  sand-washing  is  not  only  less 
laborious,  but  less  expensive  than  by  the  older  methods. 
One  man  can  wheel,  tip,  and  wash  9  to  10  cubic  yards  of 
sand  per  day  at  a  cost  of  3|d.  to  5d.  per  cubic  yard.  By 
the  older  processes  the  cost  was  from  Is.  6d.  to  3s.  per  cubic 
yard. 

The  addition  of  chalk  or  limestone  to  soft  waters  to 
prevent  the  action  upon  lead  can  scarcely  be  described  as 
a  process  of  purification,  but  inasmuch  as  it  is  a  process 
which  would  usually  be  associated  with  that  of  nitration  it 
may  be  mentioned  here.  By  the  admixture  of  limestone 
or  chalk  with  the  sand  the  acidity  of  the  water  is 
neutralised,  and  usually  a  small  amount  of  carbonate  of 
lime  passes  into  solution.  Dr.  Scatterty  (Public  Health, 
May,  1895)  describes  the  filtering  arrangements  made  to 
neutralise  the  plumbo-solvent  action  of  the  peaty  water 
supplied  to  Keighley.  He  says :  "  These  works,  completed 
at  a  cost  of  £18,000,  consist  of  three  beds  of  Welsh  coke 
(to  extract  the  grosser  peaty  impurities),  four  sandstone 
and  limestone  niters,  four  polarite  chambers,  and  a  clean 
water  reservoir.  By  this  filtration  the  acid  so  invariably 
found  in  moorland  water  supplies  is  neutralised  by  the 
limestone  of  the  niters,  and  by  this  means  it  is  hoped  to 
completely  destroy  the  solvent  action  of  the  water  on  the 
lead  piping."  At  ditherae  (Lancashire)  a  peaty  water  is 
filtered  and  rendered  incapable  of  acting  upon  lead  by  being 
passed  through  beds  of  sand,  Welsh  anthracite  coke,  and 
polarite,  the  works  costing  XI 9, 000.  This  process  removes 
the  peaty  colour,  renders  the  water  neutral,  and  increases 
the  hardness  to  2°,  which  is  found  sufficient  to  prevent 
action  upon  lead  pipes. 

Water,  when  softened  by  the  addition  of  lime,  usually 
undergoes  an  improvement  in  quality,  the  precipitate  of 
carbonate  of  lime  carrying  down  with  it  a  certain  pro- 
portion of  the  microbes  previously  suspended  in  the 
water.  The  filtration  through  sand  which  follows,  to 


PURIFICATION  OF  WATER  ON  LARGE  SCALE        277 

remove  the  last  trace  of  carbonate,  still  further  purifies 
the  water,  so  that  the  softening  process  has  a  double 
advantage.  As  this  process  is  primarily  conducted  for 
removing  the  carbonate  of  lime,  and  not  for  the  removal  of 
organic  matter,  and  is  of  very  considerable  importance,  it 
will  be  fully  considered  in  a  later  chapter. 

At  Oudshoorn  (Holland)  the  water  supply  is  being 
treated  with  ozonised  air  and  is  said  to  be  sterilised 
thereby. 

Machines  have  been  devised  for  sterilising  water  on  a 
large  scale  by  means  of  heat,  I  recently  tested  one  of 
these,  but  found  that  it  failed  to  (destroy  the  typhoid 
bacilli  which  had  been  introduced. 

Several  forms  of  high-pressure  niters  have  been  intro- 
duced into  this  country  of  recent  years,  and  have  been 
adopted  for  filtering  turbid  water  for  manufacturing  pur- 
poses. They  are  doubtless  very  useful  for  clarifying  water, 
but  my  experience  leads  me  to  the  conclusion  that  they 
may  be  worse  than  useless  if  used  for  filtering  water  for 
domestic  purposes.  In  two  instances,  recently,  I  have  had 
to  recommend  small  water  companies,  who  had  purchased 
these  filters,  to  abandon  their  use,  since  I  found  the  clarified 
water  contained  many  more  micro-organisms  per  c.c.  than 
the  unfiltered  water. 


CHAPTER  XIV. 

DOMESTIC  PURIFICATION. 

THE  water  supplied  by  a  public  company  can  scarcely  be 
considered  wholesome  if  it  requires  nitration  by  the  con- 
sumer, yet  in  many  towns  unfiltered  surface  water  is 
distributed,  and  as  this  often  contains  visible  suspended 
impurities,  some  form  of  nitration  must  be  resorted  to  if 
the  water  is  to  have  a  bright  and  pleasing  appearance. 
The  forms  of  filter  generally  -employed  for  purifying  all 
the  water  consumed  in  a  dwelling  may  be  classed  under 
two  heads — (a)  low-pressure  filters,  (b)  high-pressure  filters. 
The  latter  are  directly  in  communication  with  the  service 
pipe,  and  the  water  is  filtered  through  under  the  pressure 
in  the  main;  whilst  the  former  are  indirectly  connected 
by  means  of  a  ball-cock,  the  only  pressure  being  the  column 
of  water  in  the  filter  above  the  filtering  material. 

The  high-pressure  filters  may  contain  any  of  the  materials 
ordinarily  used  for  clarifying  water,  either  in  a  granular 
condition  and  tightly  packed  or  in  one  porous  mass. 
(Animal  charcoal,  polarite,  magnetic  carbide,  carferal, 
silicated  carbon,  etc.)  No  doubt  for  a  time  such  filters 
remove  a  considerable  portion  of  the  suspended  matter, 
but  they  can  never  be  trusted  to  remove  more  than  a 
small  portion  of  the  bacteria,  the  most  dangerous  of  the 
constituents.  The  separated  filth  accumulates,  and  to 
remove  it  there  is  usually  an  arrangement  permitting  of 
water  being  forced  through  in  the  opposite  direction, 
whereby  much  of  the  dirt  is  washed  away.  All  of  it  cannot 


DOMESTIC  PURIFICATION 


279 


be  thus  removed ;  hence  the  efficiency  of  the  filter  is  more 
or  less  rapidly  impaired,  and  the  filtering  material  requires 
constant  renewal.  Unfortunately,  purchasers  of  such 
filters  are  rarely  aware  of  this  fact,  or,  if  they  are,  the 
trouble  and  expense  causes  such  renewals  to  take  place  at 
very  long  intervals.  The  whole  system  is  wrong,  and 


FIG.  14. 

should  not  be  encouraged.  Even  if  carefully  attended  to 
such  filters  cannot  be  depended  upon  for  any  length  of 
time,  and  as  they  possess  few  advantages  over  low-pressure 
filters  their  use  should  be  abandoned.  The  best  filters  of 
this  class  are  Major  Crease's,  the  Berkefeld  and  Pasteur 
filters.  The  former  consists  of  a  stout  cylindrical  vessel 
filled  with  carferal,  a  compound  of  iron,  alumina,  and 


280  WATER  SUPPLIES 

carbon.  The  water  passes  in  from  the  main  at  one  end, 
and  out  to  supply  the  house  from  the  opposite  extremity. 
The  filtering  material  within  the  cylinder  is  packed 
between  two  perforated  plates,  one  of  which  can  be  screwed 
down  upon  the  other  so  as  to  obtain  any  required  degree 
of  compression.  It  can  also  be  readily  unpacked  for 
cleansing  or  for  renewal  of  the  carferal.  The  "  Berkefeld  " 
is,  strictly  speaking,  a  bacteriological  filter,  its  object  being, 
not  the  oxidation  of  dissolved  organic  matter,  but  the 
removal  of  the  whole  of  the  suspended  matter,  including 
the  most  minute  organisms.  The  filtering  cylinder  is  com- 
posed of  compressed  fossil  earth  (Eietelguhr),  and  the  water 
is  purified  by  filtration  through  the  side.  The  suspended 
matters  removed  from  the  water  remain  upon  the  surface, 
and  can  easily  be  washed  or  brushed  away,  and  the 
cylinders  can  be  resterilised  by  being  placed  in  warm 
water  and  boiled  for  an  hour.  Fig.  14  is  a  section  of  a 
cistern  filter  working  with  a  pressure  of  20  Ib.  upwards. 
A  3-tube  filter  of  this  kind  will  supply  50  gallons  of  water 
per  hour. 

A  smaller,  single-tube  filter  is  shown  in  Fig.  15.  It  is 
intended  for  attachment  to  the  water  supply  either  from  a 
constant  main  service,  with  a  pressure  of,  say,  30  Ib. 
upwards,  or  from  a  cistern  not  less  than  20  feet  above 
where  the  filter  is  fixed. 

The  Pasteur  or  Chamberland-Pasteur  filter  is  very  similar 
to  the  Berkefeld,  but  is  made  of  china  clay,  is  somewhat 
harder,  and  therefore  not  so  readily  fractured.  Both  are 
efficacious  at  first,  but  the  latter  is  said  to  yield  a  more 
palatable  filtrate.  To  the  use  of  the  Pasteur  filter  by  the 
French  army  during  recent  years  is  attributed  the  great 
decrease  in  the  mortality  from  typhoid  fever  amongst  the 
soldiers  (50  per  cent.).  In  other  instances,  when  used  for 
manufacturing  purposes,  their  use  has  been  discontinued 
on  account  of  the  slowness  of  the  filtration,  and  because 
after  prolonged  use  the  filtered  water  was  no  longer 


DOMESTIC  PURIFICATION 


281 


bacteriologically  satisfactory.  In  a  series  of  experiments 
made  by  Dr.  Johnston,  bacteria  were  found  in  the  water 
passing  through  a  Berkefeld  filter  within  from  3  to  10  days 
of  continuous  use.  The  Pasteur  filtrate  remained  sterile 
for  six  weeks.  Recent  experiments  made  by  Dr.  Sims 
Woodhead  (Brit.  Med.  Journal)  confirm  the  superiority  of 
the  Pasteur  filter. 


u 

FIG.  15. 

S.  Water-inlet. 
T.  Outlet  for  filtered  water. 
U.  Outlet  for  water  used  for  washing  cylinder. 

A  number  of  forms  of  these  high-pressure  filters  are 
made  for  fixing  to  taps,  pumps,  etc.  They  yield  a  water 
which  at  first  is  absolutely  free  from  micro-organisms,  and 
as  they  are  extremely  simple  in  construction  and  admit  of 
being  very  easily  cleansed,  no  other  filter  can  be  compared 
with  them  for  high-pressure  work. 

Bailey  Denton's  self-supplying  filter  may  be  taken  as 
typical  of  the  low-pressure  service  filter. 


282  WATER  SUPPLIES 

The  upper  compartment  contains  the  filtering  material, 
which  may  be  sand,  charcoal,  or  any  other  of  the  substances 
used  for  such  a  purpose,  and  is  fed  from  the  house  cistern 
at  a  higher  level.  When  the  filtered  water  in  the  tank 
below  reaches  a  certain  level  the  supply  to  the  filter  is  cut 
off,  and  the  remaining  water  as  it  drains  from  the  filtering 
material  is  replaced  by  air,  so  that  the  filter  is  frequently 
aerated.  If  fixed  in  an  easily  accessible  situation,  the 
material  can  be  examined  and  removed  for  cleansing  as 
often  as  may  be  required.  The  capacity  of  the  lower 
compartment  is  made  suitable  for  the  actual  requirements 
of  the  household. 

Rain  water  may  be  effectually  filtered  by  some  such 
arrangement  as  the  above,  and  if  for  any  reason  the 
reservoir  for  the  filtered  water  is  below  the  level  of  the 
ground,  the  water  may  be  raised  by  a  pump.  Even  with 
this  system  of  treatment  the  rain  water  should  be  collected 
by  means  of  a  "  separator,"  in  order  to  prevent  an 
unnecessary  amount  of  filth  being  passed  into  the  storage 
cistern,  which  not  only  fouls  the  water  but  causes  the  filter 
to  require  much  more  frequent  cleansing. 

The  number  of  domestic  filters  in  the  market  is  enormous, 
and  it  may  truthfully  be  asserted  that  the  majority  of  them 
are  worthless.  Some  are  intended  merely  to  remove  a 
portion  of  the  dissolved  organic  matter,  and  fail  entirely 
to  remove  any  bacteria  which  may  be  present.  Others, 
which  claim  to  remove  the  micro-organisms,  only  do  this 
imperfectly  and  for  a  short  time,  and  after  being  in  use 
for  a  period  the  filtered  water  may  actually  contain  more 
bacteria  than  were  present  in  the  unfiltered  water.  The 
use  of  such  filters  engenders  a  false  feeling  of  security, 
and  the  users  may  fall  victims  to  their  misplaced  confidence. 
I  have  had  occasion  to  examine  several  much-vaunted 
filters,  and  found  them  absolutely  useless;  thjey  were 
coarse  strainers  and  nothing  more.  The  so-called  "  table 
filters  "  are  usually  the  least  reliable,  since  the  amount  of 


DOMESTIC  PURIFICATION 


283 


filtering  material  is  too  small  to  purify  the  water  for  any 
length  of  time,  if  at  all;  and  if  the  material  be  made 
sufficiently  compact  to  prevent  the  passage  of  micro- 
organisms, the  rate  of  nitration  is  excessively  slow,  and 
the  pores  of  the  filter  become  rapidly  choked.  The 
Berkefeld  and  Pasteur  filters  are  probably  the  most 
reliable,  but  are  very  slow  in  action.  The  tubes  must  be 
frequently  removed,  washed,  first  with  water,  then  with  a 


FILTER  PAPER 


FIG.  16. 

dilute  solution  of  permanganate  of  potash,  and  finally 
sterilised  by  boiling  or  by  heating  over  a  charcoal  stove  or 
Bunsen  burner. 

For  ordinary  domestic  purposes  an  inexpensive  sand 
filter,  which  can  be  made  by  any  person  is  as  good,  or 
better,  than  many  of  the  high-priced  filters  in  the  market. 
The  following  is  a  description  of  a  cottage  filter  costing 
only  a  few  pence  :  — Take  a  large-sized  earthenware  flower- 


284  WATER  SUPPLIES 

pot,  and  plug  the  hole  at  the  bottom  with  a  cork,  through 
which  passes  a  short  piece  of  glass  tube.  Upon  the  bottom 
place  a  few  fragments  of  a  broken  flower-pot  (pieces  J  to 
J  inch  square).  Upon  these  place  a  layer  of  small,  clean- 
washed  gravel,  and  upon  this  6  to  12  inches  of  well-washed, 
fine,  sharp  sand.  Cover  the  smooth  surface  of  the  sand 
with  a  circular  piece  of  coarse  filter  paper  and  sprinkle  over 
this  a  few  pieces  of  the  small  gravel.  Mount  the  pot  on  a 
tripod  or  other  convenient  stand,  and  it  is  ready  for  use. 
The  paper  prevents  the  upper  surface  of  the  sand  being 
disturbed  by  pouring  in  the  water,  and  can  be  removed, 
together  with  most  of  the  sediment  which  has  formed 
thereon,  as  often  as  necessary.  Every  few  months,  or 
oftener  if  required,  the  sand  can  be  thoroughly  washed 
and  replaced.  A  layer  of  finely-granulated  polarite  and 
sand,  in  equal  quantities,  may  be  substituted  for  the  lower 
half  of  the  sand  layer,  and  improves  the  character  of  the 
filtered  water  in  some  instances,  especially  where  the  water 
to  be  filtered  contains  rrfuch  vegetable  organic  matter,  as 
is  usually  the  case  when  taken  from  ponds.  For  the 
polarite,  magnetic  carbide,  spongy  iron,  or  animal  charcoal 
may  be  substituted  to  suit  particular  circumstances. 
Animal  charcoal,  from  the  remarkable  power  which  it 
possesses  of  removing  certain  colouring  matters  from  water, 
and  of  absorbing  or  oxidising  organic  matters  generally, 
of  a  complex  character,  used  to  be  considered  one  of  the 
best,  if  not  the  best,  of  all  filtering  materials.  Water, 
however,  which  has  been  in  contact  with  it  forms  a 
favourable  medium  for  the  growth  of  low  forms  of  life, 
and  bacteria  grow  within  its  pores.  Professor  P.  Frankland 
found  that  for  some  days  animal  charcoal  removed  most  of 
the  bacteria,  but  that  it  gradually  lost  this  power,  and 
before  the  end  of  a  month  the  filtered  water  contained 
many  more  germs  than  the  unfiltered.  It  will  remove 
traces  of  lead,  but  this  property  it  does  not  retain  for  any 
lengthened  period.  Vegetable  charcoal,  ground  coke,  and 


DOMESTIC  PURIFICATION  285 

other  forms  of  charcoal  also  are  used  as  filtering  media, 
but  they  do  not  possess  the  decolourising  and  oxidising 
powers  of  animal  charcoal.  They  are  equally  efficacious 
in  removing  low  forms  of  life,  and  retain  this  property 
longer.  Ground  slag,  pumice,  sandstone  in  slabs,  etc.,  are 
occasionally  employed  in  niters,  but  possess  no  advantage 
over  good  sand.  Sponge  sioon  become  foul,  and  only  acts 
as  a  coarse  strainer;  its  use  is  not  recommended. 

Whatever  material  be  used,  it  must  be  remembered  that 
it  can  only  retain  its  efficiency  for  a  limited  period,  and 
no  filter  should  be  purchased  which  does  not  permit  of  the 
filtering  media  being  easily  removed  for  cleansing  or 
renewal.  The  filter  should  also  contain  a  sufficient  amount 
of  the  material  to  produce  something  more  than  a  mere 
straining  action.  If  not  of  sufficient  depth,  it  may  remove 
all  the  coarser  suspended  matters,  and  the  water  appear 
bright,  yet  the  micro-organisms  may  pass  through  with  the 
utmost  ease.  Earthenware  vessels  are  the  best  for  contain- 
ing the  filtering  medium.  Galvanised  iron  is  easily  acted 
upon,  and  may  contaminate  the  water  with  zinc.  Wooden 
casks  may  be  used  if  the  inside  has  been  previously  well 
charred,  and  if  the  charring  be  repeated  occasionally. 

When  drinking  water  is  of  suspicious  quality,  and  there 
is  the  slightest  doubt  about  the  efficiency  of  the  filtration, 
it  should  be  well  boiled  before  use,  say  for  ten  minutes. 
This  kills  everything  save  certain  very  resistant  spores ;  but 
as  there  are  good  grounds  for  believing  that  none  of  these 
spores  are  disease  producing,  their  presence  is  of  little 
consequence.  It  is  better  to  use  the  water  soon  after 
cooling  and  before  the  spores  have  had  time  to  develop. 
Boiling  also  removes  most  of  the  carbonates  of  lime  and 
magnesia,  rendering  the  water  softer ;  as  the  dissolved  gases 
are  also  given  off,  its  taste  is  flat  and  insipid.  It  can  easily 
be  again  aerated  by  pouring  through  a  cullender  or  sieve 
from  some  little  height,  when  the  finely-divided  streams  of 
water  again  take  up  gases  from  the  air. 


286  WATER  SUPPLIES 

By  distillation  a  pure  water  may  be  obtained  from  the 
sea,  and  from  other  salt-laden  or  impure  waters.  The  saline 
matters  remain  behind  in  the  boilers,  and  the  steam,  when 
condensed,  can  only  contain  any  traces  of  volatile  im- 
purities which  may  have  been  present.  These  volatile 
substances  have  been  charged  with  causing  diarrhoea,  but 
it  is  much  more  probable  that  the  illness  was  due  to 
defective  distillation  allowing  some  of  the  impure  water  to 
gain  access  to  the  vessel  in  which  the  distilled  water  was 
being  condensed  or  collected.  By  aeration  the  insipid 
flavour  of  distilled  water  may  be  improved. 

When  tea  or  coffee  is  made  with  boiling  water,  the 
astringent  matter  in  the  leaves  or  berries  may  tend  to 
produce  still  further  purification.  In  many  epidemics  of 
typhoid  fever,  it  has  been  noticed  that  persons  who  drank 
the  infected  water  only  when  made  into  tea  or  coffee 
escaped  entirely. 

Turbid  and  polluted  waters  are  sometimes  clarified  by 
the  addition  of  from  2  to  6  grains  of  alum  to  each  gallon, 
a  very  little  lime  also  being  added  if  precipitation  is  not 
sufficiently  rapid.  The  flocculent  precipitate  which  forms 
carries  down  with  it  most  of  the  bacteria.  Perchloride  of 
iron  is  sometimes  used  instead  of  alum,  and  for  the  same 
purpose. 

Where  only"  foul-smelling,  impure  water  is  obtainable, 
Dr.  Parkes  recommended  the  use  of  permanganate  of 
potassium,  which  is  the  active  ingredient  in  Condy's  Fluid. 
The  solution  of  permanganate  should  be  added  gradually 
and  with  constant  stirring,  until  a  very  faint  but  per- 
manent pink  tint  is  perceptible.  A  little  alum  is  then 
added,  and  the  water  allowed  to  clear  by  subsidence.  Such 
waters  also  are  improved  in  quality  by  being  stored  in 
well-charred  casks.  Very  foul  waters,  when  kept,  often 
undergo  a  kind  of  fermentation,  and  become  clear,  bright, 
and  palatable. 

A   method   for   sterilising   potable   water,    of   which    an 


DOMESTIC  PURIFICATION  287 

abstract  will  be  found  in  the  Journal  of  State  Medicine, 
vol.  viii.,  p.  198,  has  been  devised  by  the  chief  army  surgeon 
of  the  Prussian  army.  The  process  is  especially  adapted 
for  troops  on  the  march  or  in  camp,  and  consists  in  adding 
to  the  water  a  measured  quantity  of  bromine  dissolved  in 
bromide  of  potassium,  the-  bromine  being  subsequently 
fixed  by  the  addition  of  alkaline  bases.  It  was  found  that 
.06  gramme  of  free  bromine  was  sufficient  to  sterilise  a 
litre  of  water,  and  that  after  the  bromine  had  been 
saturated  with  the  corresponding  quantity  of  ammonia, 
the  taste  of  the  water  was  hardly  distinguishable  from  that 
of  the  original  sample,  and  that  so  little  of  the  bromine 
salt  was  present  as  to  be  without  influence  on  the  general 
health.  The  solution  of  bromine  (Br  21.91,  KBr  20, 
water  to  100  grammes)  was  contained  in  sealed  glass 
cylinders,  each  cylinder  holding  22  c.c.  It  was  found  by 
experiment  that  each  tube  was  capable  of  killing  all  the 
typhoid  and  cholera  bacilli  in  about  67  litres  of  water, 
which  had  been  artificially  infected  with  these  organisms. 
The  alkaline  mixture  was  in  the  form  of  a  powder  in 
corked  tubes,  each  charged  with  twelve  grammes.  The 
formula  of  the  mixture  was  Sodium  Sulphite  7.2,  Anhy- 
drous Sodium  Carbonate  3.0,  and  Mannite  1.8.  This 
quantity  of  powder  is  enough  to  neutralise  the  bromine 
contained  in  one  of  the  sealed  glass  cylinders. 

Drs.  Parkes  and  Rideal,  in  a  paper  read  before  the 
Epedemiological  Society  on  Jan.  18th,  1901,  recommend 
the  use  of  tabloids  of  sodium  bisulphate  for  destroying  the 
bacillus  of  typhoid  fever  in  water.  They  find  that  15 
grains  of  this  salt  added  to  one  pint  of  infected  water  kills 
the  bacillus  in  15  minutes,  and  they  express  the  opinion 
that  the  use  of  this  salt  would  diminish  the  inevitable 
suffering  of  our  soldiers  from  thirst  and  protect  them  from 
the  ravages  of  water-borne  disease, 


CHAPTER  XV. 

THE  SOFTENING  OF  HAKD  WATER. 

As  previously  explained,  the  hardness  of  water  is  due  to 
the  presence  of  compounds  of  lime  and  magnesia,  chiefly  the 
former.  The  temporary  hardness  is  due  entirely  to  the 
carbonates  of  these  bases,  whilst  the  permanent  hardness 
is  caused  by  the  sulphates,  chlorides,  and  other  salts.  The 
disadvantages  attending  the  use  of  hard  waters  have  already 
been  referred  to>,  the  chief  being  the  waste  of  soap  when 
the  water  is  used  for  certain  domestic  purposes.  With 
very  hard  waters  this  waste  is  so  great  that  it  is  much  more 
economical  to  soften  the  whole  of  a  public  supply  than  for 
each  consumer  to  soften  his  quota  by  aid  of  soda  or 
soap.  From  the  description  of  the  various  processes  in  use 
for  softening  water,  and  their  cost,  the  conditions  which 
determine  whether  it  is  advisable  to  adopt  one  or  other  of 
them  will  be  manifest. 

Water  may  be  softened — (a)  by  boiling;  (b)  by  distilla- 
tion; and  (c)  by  the  addition  of  lime*,  with  or  without 
carbonate  of  soda,  soda  ash,  or  other  chemicals. 

(a)  By  boiling,  the  carbonic  acid  gas  is  driven  off,  and  the 
carbonates  of  lime  and  magnesia  which  had  been  held  in 
solution  by  this  gas  are  deposited.  The  process  is  trouble- 
some and  expensive.  The  Rivers  Pollution  Commissioners 
calculated  that  the  fuel  (coal)  necessary  to  be  used  to  soften 
1,000  gallons  of  water  by  boiling  for  half-an-hour  would 
cest  about  7s.  6d.  The  same  quantity  of  Thames  water 
softened  by  soap  would  cost  9s.,  so  that  boiling  is  not  much 
less  expensive  than  softening  by  soap. 


THE  SOFTENING  OF  HARD  WATER  289 

(b)  Distillation  naturally  is  much  more  expensive  than 
simple  boiling,  and  would  never  be  resorted  to  simply  for 
softening  a  water.     Boiling  merely  removes  the  temporary 
hardness;   distillation  separates  all  the  saline  ingredients, 
so  that  distilled  water  is  the  softest  of  all  waters. 

(c)  By  the  addition  of  lime.     Lime  has  a  great  affinity 
for    carbonic     acid,     combining     therewith     and     forming 
carbonate  of  lime  or  chalk.     When  lime,  therefore,  is  added 
to  a  natural  water,  the  carbonic  acid  is  absorbed,  and  the 
chalk  previously  held  in  solution  thereby  is  precipitated, 
together  with  a  portion  of  the  carbonate  of  magnesia  if 
any  be  present.    The  sulphates  and  chlorides  are  unaffected, 
so  that  the  permanent  hardness  is  not  reduced.     Care  has 
to  be  taken  that  an  excess  of  lime  be  not  added,  since  it 
again  increases  the  hardness.     As  1  cwt.  of  lime,  costing  Is., 
will  soften  as  much  water  as  2  cwts.  of  60  per  cent,  soda 
ash,  costing  14s.,  or  1  ton  of  soap,  costing  over  £30,  there 
can    be    no   question    as   to   the    economy    of    using    lime. 
Dr.  Clark  was  the  original  patentee  of  the  lime  process, 
and  it  is  the  one  almost  universally  adopted.     Since  the 
lapse  of  his  patent  many  modifications  have  been  devised 
for  the  purpose  of  dosing  the  water  automatically  with  the 
proper  quantity  of  lime,  and  for  facilitating  the  removal 
of  the  carbonates  precipitated.     Most  of  these  are  more 
especially  designed  for  softening  water  for  manufacturing 
purposes  and  for  use  in  steam  boilers,  rather  than  for  water 
for  domestic  use,  but  certain  of  them  can  be  adapted  for 
either  purpose. 

In  Clark's  original  process  lime  water  was  added  to  the 
water  to  be  treated,  and  the  mixture  was  allowed  to  clear 
by  subsidence  in  large  tanks  or  reservoirs.  To  ensure 
complete  clarification  required  at  least  6  to  8  hours.  Large 
tanks  were  necessary,  and  these  had  frequently  to  be 
cleansed. 

Messrs.  John  Taylor,  Sons,  and  Santo  Crimp  have  kindly 

19 


2go  WATER  SUPPLIES 

furnished  me  with  the  following  particulars  of  the  process 
employed  by  the  Colne  Valley  Water  Company :  — 

This  company  derives  its  water  from  wells  sunk  in  the 
chalk,  and  is  at  the  present  time  supplying  upwards  of  two 
millions  of  gallons  per  diem  during  the  summer  months. 
The  whole  of  the  water  is  softened  by  Clark's  process. 
Buxton  or  other  suitable  lime  is  purchased,  brought  on  to 
the  works  and  tipped  into  a  building  marked  on  the  accom- 
panying diagram  (Fig.  17)  "  Lime  Slaking  House." 
Quantities  as  required  are  placed  in  slaking  trough  and 
slaked,  and  afterwards  water  is  added  to  bring  the  lime 
into  the  consistency  of  cream.  This  cream  of  lime  is 
passed  through  a  screen  and  allowed  to  gravitate  into  one 
or  other  of  the  "  lime  water  tanks."  The  lime  water  tank 
is  then  filled  with  softened  water  and  the  liquid  thoroughly 
agitated  by  means  of  air  which  is  forced  through  pipes 
to  the  bottom  of  the  tank  by  a  special  air  pump.  The 
liquid  lime  water  is  then  allowed  to  rest  and  clarify; 
samples  are  extracted  from  the  tank  and  tested  for 
strength,  and  if  the  solution  is  not  saturated  further  blow- 
ing with  the  air-pump  takes  place.  After  the  lime  water 
has  thoroughly  clarified  it  is  run  off  by  means  of  a  floating 
pipe  into  one  or  other  of  the  "  softening  tanks."  The 
lime  water  tank  is  again  filled  with  softened  water,  and 
the  operations  above  described  repeated.  By  means  of 
decanting  the  clear  liquid  through  the  floating  arm  the 
impurities  and  unburnt  portions  of  the  lime  accumulate 
in  the  bottom  of  the  lime  water  tanks,  and  provision  is 
made  for  cleaning  out  the  tanks  by  means  of  a  chain 
pump. 

It  will  be  seen  from  the  diagram  that  there  are  3  lime 
water  tanks,  and  these  are  used  in  rotation;  thus,  while 
one  is  filling,  a  second  is  standing  full  for  clarification,  and 
the  clear  liquor  in  the  third  is  being  withdrawn  into  the 
softening  tanks.  The  dimensions  of  each  of  these  tanks 
are  32  feet  long,  26  feet  wide,  and  19  feet  6  inches  deep. 


THE  SOFTENING  OF  HARD  WATER 


291 


T  EN  1    N 
/V«2. 

TAN 
/V«3. 

5 

/V°4 

FIG  17. 


2Q2 


WATER  SUPPLIES 


After  the  lime  water  has  been  decanted  into  one  or  other 
of  the  softening  tanks,  this  tank  is  filled  by  means  of  the 
pumping  machinery  with  the  hard  water,  and  the  agitation 
due  to  the  water  entering  the  tank  is  sufficient  to  cause  an 
intimate  mixture  with  the  lime  water.  Samples  are  tested 
from  time  to  time  as  the  filling  of  the  softening  tanks 
proceeds  to  ascertain  when  the  lime  water  which  was  first 
added  has  entirely  been  utilised  by  the  hard  water  which 
has  been  mixed  with  it,  and  when  the  action  is  complete, 
and  no  further  free  lime  is  present,  the  tank  is  shut  off 
from  the  pumps  and  the  liquid  is  allowed  to  stand  for  a  few 
hours  to  allow  the  precipitated  chalk  to  deposit.  When 
this  has  taken  place  the  clarified  liquid  is  drawn  off  from 
the  tanks  by  means  of  floating  arms,  and  is  pumped  into 
the  service  reservoirs.  When  the  liquid  has  been  drawn 
down  to  within  two  or  three  feet  of  the  bottom, 
the  tank  is  shut  off,  a  fresh  quantity  of  lime  water  is 
admitted,  and  the  operations  proceed  as  described.  There 
are  4  softening  tanks,  each  tank  being  about  85  feet  long, 
by  70  feet  broad,  by  18  feet  in  depth.  The  cycle  of  the 
4  tanks  in  general  working  is — two  standing  full  clarifying, 
one  filling,  and  one  being  emptied  after  the  water  has 
been  softened  and  clarified. 

The  exact  amount  of  lime  water  to  be  added  depends 
upon  various  circumstances,  but  in  working  practice  it  is 
found  that  with  the  particular  water  in  question  10  per 
cent,  of  lime  water  effects  the  largest  amount  of  softening. 
After  the  softening  tanks  have  been  in  use  for  a  few 
weeks  there  has  accumulated  from  2  to  3  feet  of  chalk 
deposit.  The  tank  is  then  thrown  out  of  use,  and  the  chalk 
deposit  is  pumped  into  pits,  where  it  is  allowed  to  dry 
and  accumulate. 

Modern  inventors  have  devised  means  for  dispensing 
with  the  large  settling  tanks,  and  for  ensuring  much  more 
rapid  and  complete  removal  of  the  precipitated  carbonates. 
These  processes  all  require  a  special  plant. 


THE  SOFTENING  OF  HARD  WATER  293 

In  Atkins'  process  lime  is  mixed  with  water  in  a  cylinder 
called  the  "  lime  cylinder,"  and  the  solution  so  formed 
passes  through  special  regulating  valves  into  a  "  mixer," 
in  which  it  is  mixed  with  the  water  to  be  treated  in  the 
proper  proportion.  The  mixture  then  flows  into  a  "  soften- 
ing cistern,"  in  which  a  portion  of  the  precipitated  matter 
is  deposited,  and  the  partially  clarified  effluent  is  next 
conducted  into  patent  machine  filters,  which  "  are  con- 
structed with  a  series  of  hollow  metal  discs,  covered  with 
cloth,  so  arranged  as  to  give  the  largest  possible  amount  of 
surface  in  the  smallest  space."  Sets  of  spray  pipes  are 
attached  in  such  a  manner  as  to  play  over  the  whole  sur- 
face of  the  discs  when  set  in  motion,  and  the  filters  are 
rapidly  cleansed.  At  Henley  (population  6,500)  such  an 
apparatus,  with  five  filters,  has  been  in  use  since  1S82, 
and,  according  to  Professor  Attfield's  analysis,  the  water 
is  reduced  by  the  treatment  from  19.5°  to  4.2°  of  hardness. 
At  Southampton  (population  79,000}  about  3,500,000  gal- 
lons of  water  per  day  are  softened,  and  the  plant  is  said  to 
be  the  largest  in  the  world.  It  includes  nineteen  filters,  a 
softening  tank  76  feet  by  45  feet  by  5i  feet,  four  "  lime  " 
cylinders,  mixer  and  limeh-slacking  mills,  all  comprised  in 
one  building  measuring  about  134  feet  by  48  feet.  Without 
enlarging  the  building  additional  plant  can  be  added,  so  as 
to  increase  the  supply  of  softened  water  to  5,000,000  gallons 
per  day.*  The  cost  of  softening  at  Southampton  is  Jd. 
per  1,000  gallons  for  working  expenses  and  another  Jd.  for 
interest  and  repayment  of  loans,  making  a  total  cost  of 
Jd.  per  1,000  gallons.  At  Lambeth  workhouse,  with  1,500 

*  Much  dissatisfaction  at  one  time  arose  at  Southampton  in  conse- 
quence of  the  water,  after  being  softened,  depositing  calcareous  matter 
in  the  mains,  and  not  always  being  delivered  free  from  turbidity. 
Whilst,  on  the  one  side,  this  was  declared  to  be  the  fault  of  the  process 
employed  and  insufficiency  of  the  filtering  area,  the  patentees  asserted 
that  it  was  entirely  due  to  the  careless  way  in  which  the  system  was 
worked.  Since  additional  filters  have  been  provided,  and  the  plant 
has  been  modified,  excellent  results  have  been  obtained. 


294  WATER  SUPPLIES 

inmates,  there  is  an  installation  for  softening  300,000  gal- 
lons of  water  per  day.  The  plant  occupies  a  space  of  22 
feet  by  16  feet,  and  the  only  attention  required  is  said  to 
be  the  labour  of  one  man  for  an  hour  a  day.  The  cost  of 
the  plant  was  about  £2,000,  and  the  total  expense  of  treat- 
ing the  water  supply  is  said  not  to  exceed  ,£50  per  year,  or, 
including  interest  on  capital,  about  Jd.  per  1,000  gallons. 
The  saving  in  soap,  soda,  fuel  for  boilers,  repairs  to  boilers, 
tea,  etc.,  is  believed  to  amount  to  over  XI, 000  per  year. 

The  Porter-Clark  Company  claim  that  their  system  is 
the  most  economical,  since  the  apparatus  is  of  a  very  simple 
character,  requires  very  little  labour  and  attention,  and 
works  under  pressure,  so  that  the  softened  and  filtered 
water  can  be  delivered  into  high-pressure  cisterns  without 
pumping.  It  consists  of  two  vertical  cylinders  and  a  filter 
press.  In  the  first  cylinder  there  is  a  continuous  prepara- 
tion of  lime  water.  In  the  second  the  hard  water  and 
proper  proportion  of  lime  water  are  mixed,  and  in  the 
press,  which  is  made  up  of  a  series  of  plates,  with  cloths 
interposed,  the  precipitate  formed  is  filtered  out.  Where 
large  quantities  of  water  are  being  treated,  some  motive 
power  is  required  to  keep  the  contents  of  both  cylinders 
in  a  state  of  agitation.  The  approximate  price  of  a  plant 
softening,  automatically,  1,000  gallons  an  hour,  is  £200; 
for  softening  2,000  gallons,  £280.  The  London  and  North- 
Western  Railway  Company  use  this  system  at  various 
depdts.  At  Liverpool,  Camden,  Willesden,  and  Rugby, 
about  1,000,000  gallons,  in  all,  are  softened  daily  for  use  in 
their  locomotives.  Modified  forms  of  this  apparatus  are 
made  for  special  purposes.  One  form,  which  dispenses  with 
motive  power,  save  that  of  a  man  for  a  few  minutes  daily, 
will  soften  from  500  to  2,000  gallons  of  water  per  hour, 
and  by  the  use  of  various  other  reagents  besides  lime,  such 
as  caustic  soda  and  carbonate  of  soda,  the  permanent  as 
well  as  the  temporary  hardness  can  be  reduced  where 
necessary.  The  Porter-Clark  process  has  been  adopted  in 


THE  SOFTENING  OF  HARD  WATER  295 

a  large  number  of  public  institutions,  manufactories, 
mansions,  etc. 

The  "  Stanhope  "  water  softener  (Fig.  18)  occupies  but 
little  space,  possesses  no  movable  parts,  and  no  filtering 
apparatus,  the  water  being  clarified  by  subsidence  in  special 
tanks  containing  numerous  sloping  shelves,  upon  which  the 
carbonates  are  deposited.  It  aims  at  reducing  both  the 
permanent  and  temporary  hardness,  lime  and  soda  being 
the  chemicals  used  for  this  purpose.  The  only  attendance 
required  is  that  of  a  man  to  mix  the  lime-water  and  soda 
every  few  hours,  and  to  open  the  mud  cocks  occasionally 
to  let  out  the  accumulated  precipitate.  The  cost  of  soften- 
ing by  this  process  is  stated  by  the  makers  to  average  Id. 
per  1,000  gallons,  though  this  will  depend  upon  the 
character  of  the  water  treated.  It  appears  to  be  a  favourite 
with  manufacturers,  especially  woolwashers  and  bleachers, 
and  with  large  users  of  steam  power  for  boiler  purposes. 
Quite  recently  the  Stanhope  water  softeners  and  purifiers 
have  been  considerably  improved.  For  the  sloping  shelves 
in  the  clarifying  tower  a  series  of  perforated  funnel-shaped 
cones  (Fig.  19)  have  been  substituted.  These  cause  the 
water  to  traverse  the  tower  more  slowly,  and  more  perfect 
sedimentation  results.  A  continuous  mechanical  lime 
mixer  has  also  been  added.  For  potable  purposes  some 
system  of  filtration  is  necessary  to  secure  absolute  clearness. 
The  makers  recommend  filter  presses,  since  the  work  left 
for  the  cloths  to  do  is  almost  nil,  and  they  may  be  used 
for  a  length  of  time  without  requiring  cleaning.  The 
natural  head  of  water  from  the  clarifying  tower  supplies  all 
the  pressure  necessary.  This  simple  mode  of  filtration 
may  be  sufficient  for  certain  very  pure  waters,  but  for 
contaminated  waters  sand  filtration  would  be  far  preferable. 

The  "  Howatson  "  softener  is  somewhat  similar  in  prin- 
ciple to  the  above.  The  lower  portion  of  the  apparatus 
consists  of  a  tank  divided  into  two  compartments,  each 
having  a  hopper  bottom.  Into  one  the  water  and  chemicals 


WATER  SUPPLIES 


FIG.  18.— The  "Stanhope"  Water  Softener. 


THE  SOFTENING  OF  HARD  WATER 


297 


FIG.  19.— The  "Stanhope"  Water  Softener  (Clarifying  Tower). 


2g8  WATER  SUPPLIES 

are  introduced,  and  after  chemical  action  has  taken  place 
the  mixture  passes  at  the  bottom  into  the  other,  which  acts 
as  a  "subsidence  filter."  The  lime  and  other  chemicals  are 
contained  in  two  smaller  tanks  placed  above  the  larger, 
and  which  are  used  alternately.  By  means  of  floats,  cocks, 
and  nozzles,  the  portions  of  the  chemical  solution  and  of 
the  hard  water  to  be  softened  can  be  regulated.  No 
agitator  is  required,  and  the  deposited  carbonates  are 
removed  by  occasionally  turning  the  sludge  taps  at  the 
bottom  of  the  hoppers. 

At  Stroud  Waterworks  the  water  is  softened  and  clarified 
by  a  very  simple  modification  of  Clark's  original  process, 
all  filtering  machines  being  abandoned.  By  aid  of  a  small 
water  wheel,  driven  by  the  water  to  be  treated,  two  pumps 
are  worked,  one  raising  lime  water  and  the  other  the  hard 
water.  By  altering  the  length  of  the  stroke  the  proportion 
of  the  two  can  be  adjusted,  and  as  the  rapidity  with  which 
the  wheel  rotates  depends  upon  the  pressure  of  the  water 
in  the  mains,  the  relative  quantities  of  lime  water  and 
hard  water  pumped  remain  constant.  The  treated  water 
is  clarified  by  subsidence  in  large  settling  tanks.  The 
machine  above  referred  to  will  soften  1,000,000  gallons  of 
water  per  day,  but  the  amount  actually  softened  is  only 
300,000  gallons. 

Messrs.  Archbutt  and  Deeley  have  recently  devised  an 
apparatus  which  they  regard  as  having  many  advantages 
over  others  in  the  market,  especially  for  treating  waters 
containing  magnesia  salts.  The  chemicals  used  (lime  and 
soda  ash)  are  boiled  with  water  and  then  mixed  with  the 
hard  water,  contained  in  a  tank,  by  means  of  a  steam 
"  trajector."  After  thorough  mixing,  steam  and  air  are 
forced  by  a  "  blower  "  through  perforations  in  a  series  of 
pipes  laid  close  to  the  bottom  of  the  tank.  This  stirs  up 
the  mud  and  diffuses  it  throughout  the  water,  and  when 
the  liquid  is  allowed  to  rest  precipitation  is  very  rapid. 
In  from  thirty  minutes  to  one  hour  the  water  is  almost 


THE  SOFTENING  OF  HARD  WATER  299 

perfectly  clear  and  can  be  drawn  off.  By  using  duplicate 
tanks,  one  quantity  of  water  can  be  treated  whilst  that  in 
the  other  is  undergoing  clarification.  Water  which  con- 
tains magnesia  compounds,  after  precipitation,  still  contains 
a  little  carbonate  of  magnesia,  which  rapidly  blocks  up  the 
boiler  "  injector."  To  obviate  this  the  water,  when  being 
drawn  off  from  the  settling  tank  into  the  storage  tank,  is 
dosed  with  carbonic  acid  gas  by  aid  of  a  blower.  The 
carbonic  acid  is  derived  from  the  combustion  of  coke  in  a 
special  stove.  The  water  when  sufficiently  carbonated 
no  longer  deposits  in  the  tubes.  By  this  process  the  labour 
involved  is  no  greater  for  softening  20,000  gallons  than  for 
2,000,  and  with  large  quantities  the  expense  for  labour  is 
said  not  to  exceed  £d.  per  1,000  gallons.  Some  waters  are 
found  to  clarify  much  more  rapidly  if  a  little  alum  be 
added,  together  with  the  other  chemicals,  and  this  the 
inventors  recommend  in  such  cases. 

The  cost  for  chemicals  required  to  soften  waters  of 
various  qualities  is  given  in  the  following  table  by  Messrs. 
Archbutt  and  Deeley,  and  is  quoted  here,  since  the 
chemicals  used  in  this  process  are  the  same,  both  in  quality 
and  quantity,  as  those  used  in  other  processes  which  are 
designed  to  soften  water  containing  both  lime  and  mag- 
nesia. It  will  be  observed  that  the  cost  increases  rapidly 
with  the  amount  of  sulphates  present,  especially  sulphate 
of  magnesia,  since  such  water  can  only  be  softened  by  use 
of  soda  ash  as  well  as  lime.  In  each  case  the  hardness  is 
reduced  to  from  3°  to  5°. 

The  Maignen  "  Filtre  Rapide  "  Co.  are  the  makers  of  a 
plant  which  softens  and  niters  the  water  automatically. 
By  means  of  a  small  motor  worked  by  the  flow  of  the  water 
to  be  softened,  the  proper  amount  of  "  Anti-calcaire  "  is 
added,  and  mixture  takes  place  in  a  small  tank.  From 
this  the  water  flows  to  another  tank,  where  most  of  the 
sediment  is  deposited.  Finally  it  traverses  one  of  their 
rapid  filters  and  reaches  the  storage  tank  in  a  completely 


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WATER  SUPPLIES 


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THE  SOFTENING  OF  HARD  WATER  301 

clarified  condition.  This  is  one  of  the  processes  which  can 
be  used  on  the  small  scale,  for  private  houses,  etc. 

Although  certain  of  the  processes  described  would 
appear  to  require  very  little  personal  attention,  according 
to  the  statements  of  the  inventors,  yet,  if  uniformly  satis- 
factory results  are  to  be  obtained,  there  must  be  constant 
supervision.  The  treated  water  must  be  repeatedly 
examined  to  ascertain  that  neither  too  little  nor  too  much 
of  the  lime  or  other  chemicals  is  being  added.  If  too 
little,  the  water  will  not  be  properly  softened,  and  if  too 
much,  the  water  will  be  rendered  alkaline,  and  the 
magnesia  will  not  be  removed.  When  the  amount  of  lime 
added  is  a  little  less  than  the  theoretical  quantity  required 
to  precipitate  wholly  the  lime  and  magnesia  salts,  the  two 
carbonates  separate  in  a  form  which  settles  well,  and  the 
softened  water  filters  readily.  When  the  full  theoretical 
amount  is  used,  or  a  slight  excess,  the  carbonates  deposit 
slowly,  and  in  a  form  which  rapidly  clogs  the  filters.  Even 
after  passing  the  filter,  more  magnesia  continues  to  separate 
for  from  twelve  to  twenty-four  hours.  When  spring  or 
deep-well  waters  are  being  softened,  the  best  proportions 
of  lime  water  and  spring  or  well  water  having  been  once 
determined,  it  only  remains  to  examine  the  water  occasion- 
ally to  see  that  these  proportions  are  being  maintained, 
and  that  the  lime  water  is  uniform  in  strength.  If  the 
lime  water  be  not  saturated  with  lime  it  will  be  too  weak, 
whereas,  if  by  undue  agitation  it  is  not  only  saturated,  but 
contains  lime  in  suspension,  it  will  be  too  strong.  With 
river  waters  the  case  is  often  different.  The  composition 
may  vary  considerably  with  the  season,  and,  if  a  tidal 
river,  with  the  state  of  the  tide,  and  skilled  examinations 
must  be  frequently  performed  to  ascertain  the  exact 
proportion  of  chemicals  to  be  added. 

The  Rivers  Pollution  Commissioners  state  that  at  Canter- 
bury, Caterham,  and  Tring,  the  water  is  reduced  20°  in 
hardness  by  Clark's  process,  at  a  cost  of  only  27s.  per 


3o2  WATER  SUPPLIES 

1,000,000  gallons  for  lime  and  labour.  This  may  be  taken 
as  a  fair  estimate  of  the  cost  for  lime  and  labour  of  soften- 
ing an  average  sample  of  such  hard  waters  as  are  being 
used  for  town  supplies.  Assuming  that  the  interest  of 
capital  expended  in  plant,  buildings,  land,  etc.,  increases 
the  cost  to  Id.  per  1,000  gallons,  or  £4  3s.  4d.  per  1,000,000, 
and  that  the  hardness  to  be  reduced  is  only  16°,  the  follow- 
ing may  be  taken  as  a  low  estimate  of  the  saving  effected 
by  the  softening  of  a  town  water  supply — 

Cost  of  softening  1,000,000  gallons  .         .         .£434 

Suppose  TV  only  is   used   for  washing   purposes 

(domestic  and  laundry),  and  that  half  of  this 
is  softened  with  the  cheapest  soda,  and  the 
remainder  with  soap,  the  cost  would  be,  very 

approximately £60    0    0 

Suppose  TV  be  used  in  steam  boilers,  that  steam 
coal  costs  13s.  per  ton,  and  that  25  per  cent, 
more  fuel  be  used  on  account  of  incrustation, 
the  cost  of  additional  coal  is  .  920 


Total         .         .         .      £69     2    0 

This  represents  a  saving  of  nearly  £65  per  1,000,000 
gallons,  or  of  £23,000  a  year  to  a  town  of  30,000  popula- 
tion. A  town  of  one-third  the  size  would  save  £7,000. 
Even  in  very  small  towns  the  saving  would  be  enormous. 
This  estimate  is  very  much  below  those  usually  given  by 
makers  of  softening  apparatus,  and  in  many  cases  the  cost 
of  softening  is  said  to  be  less  than  that  given  above,  and  a 
larger  proportion  of  water  may  be  used  for  washing  purposes. 
They  forget,  however,  that  all  the  water  used  for  washing 
purposes  is  not  completely  softened.  When  used  for 
personal  ablution  only  the  very  small  quantity  taken  up 
on  the  hands  is  completely  softened,  as  the  water  after  use 
is  found  to  be  only  1  to  2  degrees  softer  than  before.  The 
saving  in  the  wear  and  tear  of  boilers,  of  culinary  utensils, 
and  the  saving  in  the  consumption  of  tea,  are  also  items 


THE  SOFTENING  OF  HARD  WATER  303 

which  have  not  been  taken  into  account  in  the  above 
estimate,  yet  which  can  be  made  to  show  a  very  con- 
siderable pecuniary  balance  in  favour  of  softened  water. 
Under  the  most  adverse  circumstances,  where  the  water 
contains  both  lime  and  magnesia  salts,  and  is  "  per- 
manently "  hard,  requiring  the  use  of  soda  as  well  as  lime 
for  softening,  and  large  tanks  and  filter  beds  for  ensuring 
complete  clarification,  the  cost  could  not  exceed  Is.  per 
1,000  gallons,  and  the  saving  effected  would  be  actually 
greater  than  in  the  towns  where  the  cost  was  only  Id., 
since  the  waste  of  soda,  soap,  fuel,  etc.,  which  would  be 
prevented,  would  be  so  much  greater  in  proportion. 

The  particular  method  of  softening  best  adapted  in  any 
given  case  depends  upon  many  circumstances,  such  as  the 
character  of  the  water  to  be  softened,  the  purpose  for 
which  it  is  chiefly  required,  the  amount  of  available  space, 
the  available  motive  power,  the  amount  of  water  required, 
and  whether  for  constant  or  occasional  use.  The  cheapest 
plant,  which,  with  the  use  of  the  cheapest  chemicals,  and 
the  least  expenditure  in  labour,  will  produce  the  desired 
result,  will  naturally  be  selected,  and  this  can  only  be 
decided  upon  when  all  the  above  factors  have  been  duly 
considered.  Under  suitable  conditions  all  are  capable  of 
giving  excellent  results. 

During  the  process  of  softening,  the  bacteria  contained 
in  the  water  suffer  a  considerable  decrease  in  number. 
Apparently  these  organisms  become  entangled  in  the  pre- 
cipitate formed,  and  settle  therewith  to  the  bottom  of  the 
tanks.  Professor  P.  Frankland  found  that  by  agitating 
water  with  powdered  chalk,  the  treated  water  after 
subsidence  only  contained  about  3  per  cent,  of  the  organisms 
originally  present.  A  carefully  -  filtered  softened  water, 
therefore,  ought  to  be  practically  sterile.  With  waters  of 
a  high  degree  of  purity,  the  filtration  necessary  after 
softening  would  be  merely  to  remove  suspended  particles 
of  carbonates ;  but  where  riv«er  water,  known  tg  be  sewage 


3o4  WATER  SUPPLIES 

contaminated,  is  being  treated,  the  nitration  must  aim  at 
removing  all  the  micro-organisms  which  may  have  escaped 
precipitation,  or  have  passed  through  the  rapid  niters 
supplied  with  certain  of  the  machines — that  is,  this  rough 
nitration  must  be  supplemented  by  thorough  filtration 
through  properly-prepared  sand  filters.  A  water  which 
has  been  thus  treated  would  appear  to  be  as  safe  for 
domestic  purposes  as  our  present  scientific  knowledge 
enables  us  to  make  it. 

Mr.  Kent  makes  a  machine  in  which  water  is  softened 
and  partially  sterilised  by  heat.  The  water  flows  through 
a  coil  of  tube,  heated  by  a  gas  flame,  oil  furnace,  or  other 
source  of  heat.  The  water  at  near  boiling  point  trickles 
down  a  tube  containing  a  series  of  metal  discs,  and  upon 
these  much  of  the  lime  salt  is  deposited.  The  incoming 
cold  water  cools  the  treated  water.  This  process,  though 
less  troublesome,  is  much  more  expensive  than  softening  by 
Clark's  method. 


CHAPTER  XVI. 

QUANTITY  OF  WATER  REQUIRED  FOR  DOMESTIC  AND 
OTHER  PURPOSES. 

THE  amount  of  water  necessary  to  supply  all  the  wants  of 
a  given  population  may  be  calculated  upon  the  basis  of 
the  theoretical  requirements  of  each  individual  or  house- 
hold, plus  the  estimated  quantity  which  will  be  necessary 
for  municipal  and  manufacturing  purposes,  or  it  may  be 
calculated  upon  the  basis  of  the  amount  actually  supplied 
to  other  similar  communities.  The  results  so  obtained 
will  often  be  found  to  vary  considerably,  and  the  causes 
of  such  variation  are  very  difficult  to  explain.  The 
amount  used  in  households  similarly  circumstanced  with 
reference  to  their  supply  varies  greatly,  according  to  the 
habits  of  the  individual  members;  but  where  the  supply 
is  practically  unlimited  and  readily  available,  the  quantity 
used  is  always  greatly  in  excess  of  that  consumed  where 
the  supply  is  limited,  or  where  it  is  more  or  less  difficult 
to  obtain.  In  rural  districts,  where  water  has  to  be  pur- 
chased from  the  hawker  or  fetched  from  a  considerable 
distance,  the  amount  used  is  astonishingly  small, — that 
which  has  been  used  for  the  purposes  of  personal  ablution 
having  often  to  serve  afterwards  for  washing  the  crockery, 
and  finally  for  washing  the  floors,  etc.  In  numbers  of 
cases  I  have  found  that  the  amount  used  in  country 
cottages  could  not  have  greatly  exceeded  1  gallon  per 
person  per  day.  Of  course  neither  perfect  cleanliness  nor 
health  is  possible  under  such  circumstances.  On  the  other 

(3°5>  20 


306  WATER  SUPPLIES 

hand,  where  the  supply  is  abundant  and  easy  of  access, 
a  very  large  proportion  is  often  wasted,  and  100  gallons  or 
more  per  person  per  day  may  pass  from  the  mains  into  the 
sewers. 

The  purposes  for  which  water  is  required  may  be 
summarised  as  follows — (a)  For  drinking,  either  as  water 
or  made  into  such  beverages  as  tea,  coffee,  and  cocoa,  and 
for  cooking  purposes;  (b)  for  personal  ablution,  including 
baths;  (c)  for  household  washing,  including  cleansing  and 
swilling  of  floors,  yards,  etc. ;  (d)  for  use  in  water-closets ; 

(e)  for  the  supply  of  horses,  cattle,  and  washing  of  carriages ; 

(f)  for  watering  plants   and  gardens   in   the  dry   season; 

(g)  for  municipal  purposes,  cleansing  streets,  flushing  sewers, 
extinguishing  fires,   etc. ;    and   (h)   for  manufacturing  and 
trade  purposes.     Where  for  municipal  and  manufacturing 
purposes,  water  can  be  more  cheaply  obtained  from  wells, 
streams,  or  other  sources,  obviously  the  public  supply  of 
pure  water  needs  not  be  nearly  so  large  as  in  towns  where 
such  sources  are  not  available.     Where  subsoil  water  can 
readily  be  obtained  from  shallow  wells,  it  may  be  utilised 
for  many  of  the  above  purposes,  especially  for  the  stable 
and  garden,   and  the  demand  upon  the  public  supply  be 
further  curtailed.     The  amount  of  water  required  for  each 
of    the    above    purposes    has    been    variously    estimated. 
Professor  Rankine,  in  his  work  on  Civil  Engineering,  states 
as  his  opinion  that  10  gallons  per  head  should  be  allowed 
for  domestic  purposes,   10  gallons  for  municipal  purposes, 
and  10  gallons  for  trade  purposes  in  manufacturing  towns. 
Most     engineers,     however,      consider     the     estimate     for 
municipal  purposes  to  be  too  high,  since  in  the  majority 
of  towns  the  amount  used  does  not  exceed  3  gallons  per 
head.     For    'trade    purposes    also    Rankine's    estimate    is 
probably    excessive,    7    gallons    per    head    being    a   liberal 
allowance.     Dr.  Parkes  *  measured  the  water  expended  in 

*  Parkes'  Practical  Hygiene. 


WATER  REQUIRED  FOR  DOMESTIC  PURPOSES       307 

several  cases ;  the  following  was  the  amount  used  by  a  man 
in  the  middle  class,  who  may  be  taken  as  a  fair  type  of 
a  cleanly  man  belonging  to  a  fairly  clean  household :  — 

Gallons  Daily 
per  One  Person. 

Cooking  .     • -75 

Fluid  as  drink  (water,  tea,  coffee)          ....  -33 

Ablution,  including  a  daily  sponge  bath,  which  took 

2£  to  3  gallons 5-0 

Share  of  utensil  and  house  washing      ....         3*0 
Share  of  clothes  (laundry)  washing,  estimated      .         .         3'0 

12-0 


The  above  may  be  taken  as  a  liberal  estimate  for  domestic 
requirements  applicable  for  most  communities.  Where 
water-closets  are  introduced,  2  to  6  gallons,  according  to 
the  mode  of  flushing,  must  be  allowed ;  for  the  supply  of 
horses  and  cattle  and  use  in  garden  2  to  5  gallons;  for 
municipal  purposes  0  to  10  gallons,  and  for  manufacturing 
purposes  0  to  10  gallons.  Where  the  water  is  not 
required  for  trade  or  municipal  purposes,  a  supply  of 
from  16  to  23  gallons  per  head  will  suffice;  but  where  the 
water  is  also  wanted  for  cleansing  streets,  flushing  sewers, 
supplying  factories,  etc.,  as  much  as  40  gallons  may  have 
to  be  provided.  Allowing  2  gallons  for  unavoidable  waste, 
we  may  take  18  gallons  as  the  minimum  and  42  as  the 
maximum  supply  required  by  any  community. 

These  figures  may  be  checked  by  the  actual  amounts 
used  in  various  tdwns.  The  Rivers  Pollution  Commissioners, 
in  their  Sixth  Report,  in  discussing  the  question  whether 
a  constant  or  intermittent  supply  be  the  more  economical, 
give  two  tables — one  of  the  amount  of  water  supplied  per 
house  in  each  of  the  seventy-one  towns  with  a  constant 
supply,  and  the  other  of  twenty-four  towns  each  having  an 
intermittent  supply.  The  following  is  a  brief  summary 
of  the  tables  referred  to:  — 


303  WATER  SUPPLIES 

Constant   Intermittent 
Supply.          Supply. 
No.  of  towns  using  not  more  than  50  galls. 

per  house 3  1 

No.  of  towns  using  over  50  and  not  more 

than  75  galls,  per  house  ....  13  4 

No.  of  towns  using  over  75  and  not  more 

than  100  galls,  per  house  ...  8  2 

No.  of  towns  using  over  100  and  not  more 

than  150  galls,  per  house  ...  20  9 

No.  of  towns  using  over  150  and  not  more 

than  200  galls,  per  house  ...  10  2 

No.  of  towns  using  over  200  and  not  more 

than  300  galls,  per  house  ...  12  4 

No.  of  towns  using  over  300  and  not  more 

than  400  galls,  per  house  ...  2  2 

No.  of  towns  using  over  400  galls,  per  house  3  0 

The  mean  daily  supply  per  house  in  the  seventy-one  towns 
was  135  gallons,  in  the  twenty-four  towns  127  gallons. 
Taking  five  as  the  average  number  of  persons  per  house, 
the  mean  daily  supply  under  the  constant  system  was 
27  gallons,  and  under  the  intermittent  system  25.4  gallons. 
In  London,  with  an  intermittent  system  of  supply,  the 
average  per  person  was  40  gallons  (204  per  house). 

The  amount  of  water  supplied  per  house  under  botb 
systems  varied  enormously.  With  a  constant  supply  Hey- 
wood  and  Middlesborough  furnished  the  two  extremes.  At 
the  former  town,  with  5,200  houses  and  30  factories,  only 
20  gallons  per  house  per  day  were  consumed ;  at  the  latter, 
with  7,000  houses  and  80  factories,  the-  amount  was  700 
gallons,  or  thirty-five  times  as  much.  The  quantity  stated 
to  be  supplied  to  Heywood  is  probably  erroneous,  since 
the  Heywood  and  Middleton  Company  is  elsewhere  men- 
tioned as  supplying  7,000  houses  and  150  manufactories 
with  100  gallons  per  house  daily.  This  latter  amount 
is,  however,  only  one-seventh  that  of  the  Middlesborough 
supply,  and  the  difference  is  the  more  marked  inasmuch 
as  both  places  are  supplied  by  private  companies,  and  the 
latter  in  each  instance  are  reported  to  have  inspectors  who 


WATER  REQUIRED  FOR  DOMESTIC  PURPOSES       309 

examine  the  taps  and  fittings  to  prevent  waste.  With  an 
intermittent  supply,  Huddersfield,  with  its  8,500  houses 
and  600  factories,  only  used  49  gallons  per  house  daily, 
whilst  Berwick,  with  1,150  houses  and  7  factories,  used 
330  gallons  per  house.  That  these  enormous  differences 
depend  more  upon  the  amount  wasted  than  upon  the 
amount  used  for  either  domestic,  municipal,  or  trade 
purposes  is  almost  certain.  The  consideration  of  a  few 
more  modern  statistics  confirms  this  opinion. 

In  the  following  table  the  amount  of  water  used  daily 
per  unit  of  population  in  a  number  of  representative 
towns  is  given.  Most  of  the  figures  are  taken  from  recent 
reports  of  Medical  Officers  of  Health  or  Water  Companies. 


Town. 

Population. 

nater 
He 

ad  Daily. 

Saffron  Walden    . 

6,108 

11 

gallons 

Melrose 

1,300 

13 

Bridlington  . 

9,806 

16 

Halstead 

6,100 

17 

',' 

Chepstow 

3,387 

15  to  16 

M 

East  Ham    . 

.       33,000 

20 

}, 

5,000 

20 

St.  Austell    . 

3,400 

21 

M 

Chelmsford  . 

.       11,079 

23 

n 

Bristol 

,  .  v       .     222,000 

23 

» 

Bedford 

"  .  '       .       28,023 

25 

Weston-super-Mare 

.       15,869 

26 

" 

Swansea 

93,864 

27 

Barking 

.       15,115 

26  to  30 

," 

Nottingham 

.     211,984 

28^ 

f        >l 

Wolverhampton  . 

.       82,620 

29 

,, 

Grantham    . 

16,746 

30 

» 

Yeovil 

9,648 

31 

,, 

Walthamstow 

,V.V       .       49,400 

36 

» 

The  variations  here,  though  not  nearly  so  great  as  in  the 
River  Pollution  Commissioners'  table,  are  still  very  con- 
siderable. Having  recently  to  make  an  examination  of  the 
Halstead  supply,  I  verified  the  above  figures.  The  supply 


3io  WATER  SUPPLIES 

there  is  constant,  and  the  water  is  used  for  flushing  sewers, 
watering  the  streets,  etc.,  -as  well  as  for  flushing  water- 
closets,  and  other  domestic  purposes.  In  this  town  a  large 
proportion  of  the  women  is  engaged  during  the  week  at 
the  crape  factories,  and  Saturday  is  the  great  washing-day. 
The  amount  used  on  a  Saturday  was  as  under :  — 

From  8  A.M.  to  2  P.M.        .         .         .         9,800  gallons  per  hour 
„      2  P.M.  to  4  P.M.        .         .         .         9,500       „ 
„      4  P.M.  to  5  P.M.        .         .         .         6,000       „  „ 

The  average  amount  used  on  a  week-day  was  104,000 
gallons,  and  on  Sundays  84,000  gallons.  Small  as  this 
amount  appears,  there  is  no  doubt  that  a  considerable 
portion  was  wasted,  since  many  thousands  of  gallons  passed 
from  the  service  reservoir  during  the  night,  when  little  or 
none  was  being  used. 

At  Wolverhampton  the  careful  records  kept  at  the 
Corporation  Waterworks  show  that  in  1868  "  the  domestic 
consumption  per  head  of  consumers,  deducting  for  trade 
purposes,  street  watering,  etc.,"  was  18  gallons.  In  1892 
it  had  increased  to  about  23  gallons.  In  the  latter  year  the 
total  amount  supplied  for  all  purposes  was  about  29  gallons 
per  head  daily. 

At  Newcastle  the  consumption  per  head,  for  all  purposes, 
in  1863  was  28  gallons;  in  1881  it  had  increased  to  38J 
gallons.  "  This,"  says  Dr.  Armstrong,  the  Medical  Officer 
of  Health,  "  shows  an  increase  of  37  per  cent,  in  the 
amount  consumed  for  each  person,  due;  no>  doubt,  largely 
to  improved  habits  of  cleanliness  among  the  people.  Look- 
ing at  the  fact  that  baths  and  water-closets,  which  even 
then  were  considered  as  luxuries,  are  now  regarded  as 
necessities  in  almost  every  house  of  any  pretensions  to 
comfort,  ...  it  is  not  too  much  to  assume  that  there  will 
be  a  still  further  increase  in  the  consumption  per  head." 
No  doubt  this  in  a  measure  is  true,  but  it  is  at  least 
probable  that  much  of  this  increased  consumption  is  really 


WATER  REQUIRED  FOR  DOMESTIC  PURPOSES       311 

increased  waste,  consequent  upon  the  increased  age  of  the 
mains  and  fittings.  In  London,  by  greater  attention  to 
the  sources  of  waste,  the  net  supply  per  head  of  population 
has  in  many  cases  been  very  considerably  decreased.  The 
following  table  *  is  interesting  as  showing  the  actual  amount 
of  water  supplied  daily  by  the  London  Companies  and  the 
wide  difference  in  the  supply  per  head. 


Name  of  Company. 

Net  Supply 
Daily. 

Population. 

Net  Supply 
per  Head. 

New  River  . 

32,640,976 

1,159,260 

28-16 

East  London 

39,704,601 

1,158,500 

34-27 

Chelsea 

9,557,388 

287,362 

33-25 

West  Middlesex 

15,419,907 

577,235 

26-71 

Grand  Junction 

16,701,734 

350,000 

47-72 

Lambeth 

20,234,560 

655,921 

30-85 

Southwark  and  Vauxhall 

24,373,348 

841,989 

28-94 

Kent    .... 

12,530,891 

460,524 

27-21 

171,163,385 

5,490,791 

31-19 

Of  this  quantity  it  is  estimated  that  about  20  per  cent., 
or  between  6  and  7  gallons  per  head,  is  used  for  trade  and 
municipal  purposes.  Whilst  the  West  Middlesex  Company 
supply  only  27  gallons  per  head,  the  Grand  Junction 
Company  supply  48  gallons,  and  this  the  engineer  of  the 
latter  company  explained  to  be  chiefly  due  to  waste,  since 
they  found  it  cheaper  to  pump  water  than  to  supervise 
and  control  the  waste. 

The  following  table  is  taken  from  a  paper  by  Mr.  T. 
Duncanson,  A.M.I.C.E.,  on  "  The  Distribution  of  Water 
Supplies,"  read  before  the  Liverpool  Engineering  Society, 
April,  1894. 


*  Report  of  Royal  Commission  on  Metropolitan  Water  Supply,  1893, 


3I2 


WATER  SUPPLIES 


Name  of  Company 
or  Town. 

Year. 

Domestic 
Supply  in 
Gallons 
per  Head. 

Trade 
and  Public 
Supplies. 
Gallons 
per  Head. 

Total 
Gallons 
per  Head. 

Percent- 
age of 
Supply. 
Given 
Constant. 

Liverpool 

1893 

17-10 

9-8 

26-9 

100 

Bradford 

1891 

18  to  20 

20-0 

38  to  40 

100 

Manchester 

1893 

15-0 

9-0 

24-0 

100 

Birmingham 

1893 

17-0 

8-75 

25-75 

100 

Glasgow  . 

1893 

36-0 

16-0 

52-0 

100 

St.  Helens 

1893 

18  to  21 

18  to  20 

36  to  41 

100 

Swansea 

1893 

23-4 

4-2 

27-6 

32 

All  waste  is  included  in  the  amount  set  down  for  domestic 
supply. 

The  amount  of  water  supplied  per  head  per  day  in  many 
cities  in  the  United  States  is  enormous.  The  following 
figures  are  taken  from  Vol.  xxxix.  of  the  Engineering 
Record  (p.  322).  New  York  in  1870  used  82  gallons  per 
head  per  day,  in  1899  the  amount  had  risen  to  119  gallons. 
In  Boston,  in  1895,  90  gallons  were  supplied  and  used  as 
under :  — 


For  municipal  purposes 
For  trade  purposes 
For  domestic  use 
Unavoidable  (?)  waste  . 


5  gallons 
30       „ 
40       „ 
15       „ 

90 


In  Philadelphia  (Engineering  Record,  vol.  xxxix.,  p.  430) 
no  less  than  230  gallons  are  supplied,  but  it  is  stated  that 
half  to  two-thirds  is  recklessly  wasted.  On  the  other  hand, 
certain  continental  cities  have  a  much  more  limited  supply 
than  London.  In  Berlin,  for  example,  the  daily  supply  is 
said  to  be  only  20.56  gallons  per  head  per  day,  20  per  cent, 
being  used  for  municipal  purposes  and  80  per  cent,  for 
domestic  purposes. 

Waste  of  water  arises  from  two  distinct  groups  of  causes 
— (a)  those  over  which  the  consumer  has  no  control,  and  (b) 


WATER  REQUIRED  FOR  DOMESTIC  PURPOSES       313 

those  under  the  control  of  the  consumer.  As  a  rule  the 
latter  causes  are  responsible  for  the  larger  portion  of  the 
waste.  Under  (a)  are  included  leakages  from  faulty  mains 
and  service  pipes,  and  all  other  hidden  defects,  where  the 
water  escapes  unperceived  into  drains  and  sewers  or  into 
the  subsoil;  under  (b)  the  waste  from  defective  house 
fittings,  leaving  taps  open,  etc.  Such  waste  is  also  sup- 
plemented by  an  unnecessarily  great  consumption,  due  to 
the  use  of  imperfect  appliances,  such  as  many  forms  of 
closet  basin,  and  flushing  tanks,  the  automatic  flushing  of 
urinals,  and  to  the  use  of  water  for  gardens,  fountains,  and 
similar  purposes. 

By  the  employment  of  a  staff  of  inspectors  the  waste 
arising  under  (b)  may  be  in  a  great  measure  controlled,  but 
something  more  is  required  for  the  discovery  and  check  of 
that  arising  under  (a).  By  the  use  of  water-waste  meters 
or  detectors  the  particular  branch  mains  from  which  the 
water  is  escaping  can  be  discovered,  and  by  the  aid  of  an 
instrument  resembling  a  large  stethoscope  the  faults  can  be 
localised.  The  "  Deacon,"  "  Tyler/'  "  Kennedy,"  and 
"  Ginman  "  waste  detectors  are  those  best  known.  These 
meters  register  automatically  and  continuously  the  rate  at 
which  the  water  is  passing  through  the  mains  to  which 
they  are  attached.  It  can  thus  be  ascertained  whether  the 
draught  has  been  excessive  at  any  particular  time,  or 
whether  this  is  constantly  high.  The  number  of  houses 
supplied  through  each  meter  being  known,  it  is  easy  to 
decide  whether  the  amount  of  water  which  has  passed  is 
in  excess  of  their  requirements.  If,  after  an  examination 
of  the  fittings  and  rectification  of  visible  defects,  waste  still 
continues,  the  mains  and  service  pipes  require  attention. 
If  the  ear  be  applied  to  the  service  pipes  near  where  they 
emerge  from  the  ground,  any  escape  of  water  from  the  pipe 
or  main  in  the  immediate  neighbourhood  can  be  heard,  the 
more  distinctly  the  nearer  the  defect.  The  ear  can  also  be 
applied  to  the  uncovered  main  for  a  similar  purpose,  but  it 


3i4  WATER  SUPPLIES 

is  often  more  convenient  to  apply  it  indirectly,  using  a 
walking-stick  or  a  special  instrument.  Upon  placing  one 
end  on  the  exposed  main  and  the  other  to  the  ear,  the 
fault,  if  any,  can  be  localised.  I  am  informed  that  an. 
experienced  man  can  during  the  quiet  hours  of  the  night 
detect  defects  by  listening  with  this  instrument  in  contact 
with  the  ground  over  the  mains. 

Mr.  E.  Collins,  M.I.C.E.,  in  a  paper  recently  read  before 
the  Institution  of  Civil  Engineers,  on  "  The  Prevention 
and  Detection  of  Waste  of  Water,"  says  that  a  4-inch 
Deacon's  meter  will  control  400  to  500  houses,  but  that 
smaller  districts  are  preferable.  The  outlay  involved  is 
considerable,  averaging  £150  for  each  1,000  houses  con- 
trolled. This  sum  includes  the  cost  of  the  meters  and  of 
fixing  them  on  a  by-pass,  and  of  the  valves  necessary  for 
isolating  the  divisions  of  the  district.  Where  the  meters 
are  in  use,  however,  a  much  smaller  staff  of  inspectors  is 
necessary,  since  a  glance  at  the  meters  enables  the  inspector 
to  discover  the  locality  in  which  waste  is  taking  place.  At 
Shoreditch,  as  previously  mentioned,  Mr.  Collins  was  able 
in  three  years  to  so  reduce  the  waste  as  to  save  annually 
720,000,000  gallons  of  water.  This  was  effected  by  a  capital 
outlay  of  £1,800,  and  an  annual  expenditure  of  £926  for 
staff  and  establishmental  expenses.  Each  1,000,000  gallons 
saved  cost  therefore  about  £1  9s.  Small  as  this  sum 
appears,  it  is  probable  that  it  exceeds  the  cost  of  pumping, 
especially  if  the  most  modern  machinery  be  employed. 
The  prevention  of  waste  can  only  be  accomplished  by  the 
expenditure  of  money,  and  whether  it  be  more  economical 
to  allow  the  waste  to  continue  or  to  control  it  depends 
upon  circumstances  varying  from  place  to  place,  and  it  is 
only  after  a  careful  consideration  of  these  that  it  can  be 
determined  in  any  given  district  which  is  the  cheaper. 

When  inquiries  are  made  to  ascertain  the  cause  of  the 
variation  in  the  amount  supplied  in  different  towns,  it  is 
found  that  only  on  the  assumption  that  it  is  due  to  the 


WATER  REQUIRED  FOR  DOMESTIC  PURPOSES       315 

varying  quantity  wasted  can  an  explanation  be  offered. 
Some  towns,  with  manufactories  using  large  quantities  of 
water,  use  less  in  proportion  to  the  population  than  others 
in  which  there  are  few  or  no  manufactories.  Towns  in 
which  there  are  very  few  water-closets  often  us©  more  than 
towns  in  which  water-closets  are  universal.  Where  the 
closets  are  chiefly  flushed  by  hand  more  water  may  be  used 
than  where  all  have  got  a  supply  laid  on.  Where  no  water 
is  used  for  sewer  cleansing  more  is  often  used  than  where 
flushing  arrangements  are  fixed  at  the  end  of  every  sewer. 
Where  water  from  the  mains  is  used  for  street  cleansing 
and  road  watering,  less  is  often  actually  used  than  in  towns 
which  obtain  water  for  these  purposes  from  other  sources. 
In  every  town,  moreover,  there  is  a  great  outcry  about  the 
amount  wasted,  and  we  can  only  conclude  therefore  that 
since  no  other  factor  or  combination  of  factors  will  explain 
the  difference  in  the  amount  supplied  per  head  daily,  that 
this  must  be  attributed  chiefly  to  waste.  Such  being  the 
case  it  is  evident  that  the  amount  of  water  necessary  for  the 
supply  of  a  town  is  very  much  less  than  the  estimates  given. 
Probably  20  gallons  per  head  daily  would  be  an  abundant 
supply  for  all  purposes  in  the  majority  of  cases,  and  30 
gallons  only  be  required  in  exceptional  instances.  To 
prevent  waste  and  unnecessary  consumption,  however,  so 
that  the  above  quantities  may  suffice,  the  whole  of  the 
works  in  the  first  instance  would  have  to  be  most  carefully 
constructed,  means  taken  to  quickly  detect  where  waste  is 
occurring,  constant  supervision  exercised  over  all  house 
fittings,  and  all  undue  consumption  checked  by  byelaws, 
or  by  insisting  upon  the  use  of  water  meters  by  large 
consumers. 

Few  persons  realise  the  immense  amount  of  water  which 
is  wasted  in  almost  every  town.  Thus  in  Liverpool,  where 
the  average  amount  supplied  daily  per  head  was  33.5 
gallons,  Deacon's  water-waste  detectors  were  introduced, 
and  these,  together  with  efficient  inspection,  reduced  the 


316  WATER  SUPPLIES 

supply  to  23  gallons  without  any  restrictions  being  placed 
upon  the  consumers.  At  Shoreditch,  with  a  population  of 
87,000,  the  introduction  of  waste  detectors  effected  in  the 
course  of  three  years  a  diminution  of  waste  and  undue 
consumption  amounting  to  720,000,000  gallons  per  annum, 
or  23  gallons  per  head  daily.  Mr.  Boulnois  recommended 
the  use  of  Deacon's  meters  at  Exeter,  and  their  introduc- 
tion reduced  the  waste  from  75  to  12  gallons  per  head  per 
day. 

In  other  parts  of  London,  in  Bradford  and  elsewhere, 
where  waste  detectors  have  been  introduced,  the  expendi- 
ture of  water  has  been  reduced  by  from  one-third  to  one- 
half. 

A  most  instructive  instance  of  what  can  be  done  by 
checking  waste  was  given  by  Mr.  Hawksley  in  evidence 
before  the  River  Pollution  Commission.  He  said  that 
when  "  the  city  of  Norwich  Waterworks  were  transferred 
from  a  very  old-fashioned  company  to  a  new  one  .  .  .  the 
delivery  amounted  to  40  gallons  per  head  per  diem,  and 
that  amount  of  consumption  exhausted  all  their  pumping 
power.  They  obtained  a  very  good  manager,  and,  under 
my  advice,  they  applied  for  an  additional  Act  of  Parliament 
to  enable  them  to  correct  the  fittings.  .  .  .  The  bill  was 
carried,  and  it  was  put  into  operation,  and  now  and  for 
many  years  past,  although  the  constant  supply  has  been 
unfailingly  in  use,  the  water  is  never  shut  off,  and  the 
consumption  has  descended  to  15  gallons  per  head  per  diem, 
as  compared  with  40  previously."  In  many  cases  a  check 
is  placed  upon  waste  by  placing  in  the  service  pipe  leading 
to  the  house  cistern  a  disc  with  a  small  hole  in  it,  which 
prevents  more  than  a  certain  amount  of  water  passing 
through  in  a  day.  This,  however,  is  a  most  objectionable 
arrangement,  and  quite  unnecessary,  since  better  results 
are  obtained  by  adopting  regulations  as  to  the  strength, 
proportion,  and  quality  of  the  fittings,  and  enforcing  the 
regulations. 


WATER  REQUIRED  FOR  DOMESTIC  PURPOSES       317 

In  America  water  meters  are  being  largely  used  to 
prevent  waste,  and  with  great  advantage.  For  example,  in 
Milwaukee  before  meters  were  generally  adopted  the  water 
used  per  tap  was  1,781  gallons  per  day.  Now,  when  the 
great  majority  of  houses  are  furnished  with  meters,  the 
amount  used  per  tap  is  only  644  gallons. 

In  tropical  climates,  doubtless,  the  demand  for  water  is 
greater,  and  probably  even  30  gallons  per  head  per  day 
would  be  barely  sufficient.  In  Bombay  40  gallons  is 
supplied,  and  in  Calcutta  35.4  gallons  of  filtered  water  and 
8.9  gallons  of  unaltered,  total  44.3  gallons;  but  in  many 
other  cities  the  amount  used  falls  far  short  of  this.  In 
Madras,  for  instance,  only  about  18  gallons  is  supplied; 
but  this  is  very  probably  far  too  little  for  all  the  require- 
ments of  the  population. 

The  amount  of  water  required  by  various  animals  natur- 
ally varies,  chiefly  with  the  size.  Cavalry  horses  are 
allowed  8  gallons,  and  artillery  horses  10  gallons  per  day. 
Elephants  require  at  least  25  gallons,  camels  10  gallons, 
and  oxen  6  gallons  per  head  daily. 

By  a  careful  study  of  the  requirements  of  any  community 
the  amount  of  water  which  must  be  supplied  daily  may  be 
estimated  with  a  fair  approach  to  accuracy;  but  whilst 
every  care  is  taken  to  avoid  waste,  it  must  be  remembered 
that  this  cannot  be  entirely  prevented,  and  that  it  is  far 
wiser  to  provide  a  supply  in  excess  of  the  requirements,  so 
as  to  be  prepared  for  contingencies,  and  for  a  possible 
increase  in  the  demand,  from  growth  of  population  and 
other  causes. 

The  amount  of  water  used  per  week  throughout  the  year 
does  not  vary  greatly,  but,  as  a  rule,  more  water  passes 
through  the  mains  in  summer  than  in  winter.  In  Liver- 
pool, during  1893,*  the  maximum  consumption  took  place 
in  the  week  ending  8th  July,  and  was  about  15  per  cent, 
above  the  average,  and  the  minimum  during  March, 

*  Duncanson,  loc.  cit. 


318  WATER  SUPPLIES 

November,  and  December,  and  was  about  9  per  cent,  below 
the  average.     (Vide  Chapter  XXI.) 

In  small  towns  and  rural  districts  where  a  large  number 
of  houses  have  gardens  attached,  the  summer  consumption 
of  water  is  often  greatly  in  excess  of  that  used  in  winter. 
The  most  stringently  enforced  regulations  often  fail  to 
prevent  water  being  used  in  excess  for  gardening  purposes 
during  seasons  of  drought,  and  such  misuse  of  the  water 
by  persons  living  in  the  lower  portions  of  a  district  may 
deprive  those  residing  upon  higher  ground  of  the  supply 
to  which  they  have  an  equal  right. 


CHAPTER  XVII. 

SELECTION  OF  SOURCES  OF  WATER  SUPPLY  AND  AMOUNT 
AVAILABLE  FROM  DIFFERENT  SOURCES. 

WHERE  there  is  only  one  source  of  water  available  there 
is  no  question  of  selection,  since  there  is  no  choice.  Such 
instances,  however,  are  comparatively  rare :  usually  there 
are  more  sources  than  one  from  which  water  can  be 
obtained;  and  in  deciding  upon  one  or  another  many 
points  have  to  be  considered.  A  water  seriously  con- 
taminated with  sewage  or  intermittently  liable  to  such 
contamination,  water  containing  mineral  matter  in  ex- 
cessive quantity  or  of  deleterious  quality,  and  water  with 
any  marked  odour  or  colour,  would  naturally  be  at  once 
rejected.  Cceteris  paribus,  the  water  of  greatest  hygienic 
purity  and  best  adapted  for  manufacturing  purposes  would 
be  selected.  Where  the  available  quantity  or  economy  in 
utilisation,  or  both,  are  in  favour  of  a  water  from  a  certain 
source^  the  importance  of  these  factors  must  not  be  allowed 
to  outweigh  those  of  purity  and  freedom  from  risk.  As  the 
characteristics  of  good  drinking  waters  and  the  dangers 
attendant  upon  the  use  of  polluted  waters  have  already 
been  discussed,  it  is  not  necessary  to  do  more  than  refer  to 
them  here,  special  attention  being  directed  to  the  sections 
dealing  with  river  water,  the  self-purification  of  rivers,  and 
the  discussion  of  the  risks  involved  in  the  utilisation  of 
river  waters  admittedly  polluted,  even  when  the  intake  is 
many  miles  below  the  source  of  pollution  and  the  filtration 
is  conducted  according  to  most  modern  methods.  Where 

(319) 


320  WATER  SUPPLIES 

towns  of  any  magnitude  are  concerned,  the  subject  is 
so  important  that  the  services  of  experts — engineering, 
medical,  and  chemical — would  naturally  be  enlisted ;  and 
by  these  all  the  advantages  and  disadvantages  of  the 
different  available  sources  would  be  carefully  considered, 
and  the  decision  arrived  at  would  be  based  upon  the  facts 
recorded  and  the  opinions  expressed  in  their  reports.  The 
nature  of  much  of  this  evidence  may  be  inferred  from  the 
sections  treating  of  the  quantity  and  quality  of  water 
obtainable  from  various  sources,  since  the  information  there 
given  is  of  general  application.  The  estimates  of  cost  of 
collecting,  storing,  and  distributing  will  vary  in  each 
individual  case,  and  certain  points  bearing  upon  these 
questions  will  now  be  briefly  considered. 

In  the  first  instance,  however,  it  will  be  better  to  consider 
£he  simplest  case — that  of  providing  a  supply  of  water  for 
a  single  house  or  small  group  of  houses.  In  this,  as  in 
undertakings  of  greater  magnitude,  some  knowledge  of  the 
geology  of  the  district  is  in  most  cases  absolutely 
necessary.  Without  this  the  search  for  underground  water 
is  mere  groping  in  the  dark,  which  may  or  may  not  be 
successful.  Where  a  spring,  however,  is  available,  doubtless 
this  will  be  at  once  selected,  especially  if  it  arises  at  such 
an  elevation  as  to  be  capable  of  supplying  the  house  or 
houses  by  gravitation.  In  examining  any  district  for  the 
discovery  of  springs,  the  sides  of  all  streams  should  be 
carefully  examined,  and  all  tributary  rivulets  should  be 
followed  up  to  their  respective  sources.  If  the  flow  of  the 
stream  appears  to  be  considerably  augmented  at  any  point, 
it  is  probably  due  to  the  influx  of  water  from  a  spring, 
which  may  permit  of  being  tapped  above  the  point  of 
discharge.  In  this  case  the  construction  of  a  reservoir 
large  enough  to  hold  at  least  a  day's  supply  and  the  laying 
of  a  service  main  is  all  that  is  required.  One  great 
mistake  is,  however,  frequently  made  in  this  simple  arrange- 
ment. The  pipe  is  rarely  of  sufficient  size,  and  sometimes 


SOURCES  OF  WATER  SUPPLY,  ETC.  321 

is  not  of  suitable  material.  Galvanised  iron  pipe  of  1 
inch  or  even  less  diameter  is  often  employed  to  convey 
water  considerable  distances.  If  the  water  contains  little 
or  no  carbonate  of  lime,  the  zinc  will  almost  certainly  be 
dissolved  and  contaminate  the  water.  The  pipe  then 
becomes  coated  with  a  deposit  of  iron  oxide,  which  tends 
continually  to  increase,  and  ultimately  the  calibre  of  the 
tube  becomes  too  small  to  convey  the  required  quantity  of 
water.  I  have  known  many  cases  in  which  such  pipes 
have  had  to  be  taken  up  and  larger  ones  substituted.  Cast- 
iron  pipes  coated  inside  with  Angus  Smith's  protective 
varnish  should  be  used,  and  the  diameter  should  never  be 
less  than  2  inches.  Where  water  is  required  for  fire- 
extinguishing  purposes  also,  the  diameter  of  the  pipe  must 
be  considerably  greater,  and  the  reservoir  must  be 
much  larger.  The  size  of  'main  required  under  different 
circumstances  will  be  discussed  when  the  "  distribution  of 
water  "  is  being  considered. 

The  character  of  the  water  yielded  by  springs  from 
different  geological  formations  has  been  discussed  in 
Chapter  V.,  and  the  variable  yield  from  certain  springs 
have  also  been  referred  to.  Before  attempting  to  utilise 
any  spring  as  a  source  of  water  supply  evidence  should  be 
obtained  proving  that  even  after  periods  of  continued 
drought  the  yield  is  sufficient  for  the  purposes  required. 
Many  springs  which  flow  freely  in  the  late  winter,  spring, 
and  summer  fail  completely  in  the  autumn,  or  at  least 
yield  a  greatly  diminished  supply.  The  evidence  of  people 
who  may  have  used  the  spring  or  observed  the  flow  for 
many  years  will  have  some  weight,  but  must  not  be  too 
implicitly  relied  upon.  The  flow  should  be  gauged  from 
time  to  time  and  the  effect  of  the  rainfall  ascertained, 
bearing  in  mind  that  the  flow  may  not  be  affected  by  even 
long  continued  heavy  rains  until  after  the  lapse  of  some 
months,  and  that  the  effect  of  a  long  continued  drought 
may  not  be  observed  until  long  after  it  fyas  passed  away. 

21 


322  WATER  SUPPLIES 

The   less   variable   the   flow,    the    more   likely  is   it   to   be 
constant;  the  longer  the  interval  between  a  heavy  rainfall 
or  a  drought  and  the  production  of  any  effect  upon  the  flow, 
the  less  likely  is  such  an  effect  to  be  serious.     As  a  rule 
land  springs  flow  most  copiously  in  February  and  March, 
and  are  lowest  in  October  and  November.     The  gaugings 
therefore  in  the  autumn  and  early  winter  are  the  most 
important,    since    the   minimum    flow    is    the    information 
required.     If  the  character  of  the  previous  summer  be  also 
taken  into  account  reliable  inferences  may  be  drawn  from 
the  results.     Small  springs  may  be  gauged  by  ascertaining 
the  number  of  seconds  required  to  fill  a  bucket  of  known 
capacity,  or  better  still  by  employing  a  large  vessel,  such  as 
a  tank  or  tub.     Or  the  water  may  be  caused  to  flow  along 
an  open  channel,   or  trough,   when  the  cross  section   and 
velocity  of  the  water  in  the  trough  can  be  ascertained,  and 
an    approximate    estimate    of    the    flow    easily    calculated. 
Larger  springs  may  be  gauged  by  damming  up  the  water 
and  allowing  it  to  discharge  over  a  board  from   which  a 
rectangular  notch  has  been  cut.     The  notch  should  be  two 
or  more  inches  wide  and  the  edges  chamfered.     The  prin- 
ciple involved  is  the  same  as  that  already  described  for 
gauging  streams,  and  the  height  of  the  horizontal  surface 
of  the  water  behind  the  dam  above  the  lip  of  the  notch 
being    measured,    the    flow    can    be    ascertained    from    the 
formula    there     given.     The     following     table     gives     the 
discharge  in  gallons  per  minute  and  per  day  over  a  notch- 
board  for  each  inch  of  width,  and  for  varying  differences  of 
level.     The  quantity  given  in  the  table,  multiplied  by  the 
width  of  the  notch  used,  in  inches,  will  give  the  yield  of 
the  spring  at  the  time  of  gauging.     With  notches  exceeding 
3  inches  in  width  the  results  may  be  relied  upon;    with 
narrower  notches  they  are  not  quite  so  reliable.     Moreover, 
where  the  flow  is  so  small  that  a  notch  of  less  than  3  inches 
is  required,  the  simpler  plan  of  actual  measurement  is  much 
preferable. 


SOURCES  OF  WATER  SUPPLY,  ETC. 


323 


Depth. 

Flow  per 
Minute. 

Flow  per  Day. 

Depth. 

Flow  per 
Minute. 

Flow  per  Day. 

j 

•31 

446 

9 

9-8 

14,112 

I 

•88 

1,267 

3 

12-9 

18,576 

| 

1-62 

2,333 

»J 

16-3 

23,472 

1 

2-50 

3,800 

4 

19-9 

28,656 

!i 

3-48 

5,011 

4* 

23-8 

34,272 

1£ 

4-57 

6,580 

5 

27-8 

40,032 

If 

5-76 

8,294 

5| 

32-1 

46,224 

2 

7-0 

10,080 

6 

36-6 

52,704 

It  is  a  noteworthy  fact  that  although  springs  are  not 
abundant  on  the  chalk  formation,  yet  some  of  the  largest 
springs  in  the  country  arise  in  the  chalk. 

Where  a  spring  is  not  available  attention  will  probably 
be  next  directed  to  the  subsoil  as  a  convenient  source  of 
supply,  in  which  case  a  slight  knowledge  of  the  geology  of 
the    district    may    be    invaluable.     The    points    to    which 
attention  must  be  directed  have  been  referred  to  in   the 
chapter  treating  of  "  subsoil  water."     The  character  of  the 
strata   within  reach   being  known,   and   the   directions   in 
which  they  dip  and  the  depth  and  position  of  the  nearest 
wells  having  been  ascertained,  the  presence  or  absence  of 
water  at  any  particular  spot  may  usually  be  predicted,  as 
well  as  the  depth  at  which  it  will  be  reached.     Where  the 
subsoil  is  permeable  and  the  water  held  up  by  an  imper- 
vious   stratum    beneath,    depressions    in    the    ground,    and 
spots   upon  which  herbage  is   most   abundant  or   appears 
greenest,  will  often  indicate  where  the  water  most  nearly 
approaches   the   surface.     At   sunrise  and   sunset   films   of 
vapour  (mist)  usually  arise  first  over  the  damper  portions 
of  an  area,  and  continue  of  greater  density  there  than  else- 
where.    "  On  a  dry  sandy  plain,  morning  mists  or  swarms 
of  insects  are  said  sometimes  to  mark  water  below  "  (Parkes). 
Near  streams  and  near  the  coast  water  is  generally  found 
at    a    slight    depth.      This    is    the    subsoil    water    flowing 
towards  its  natural  outlet.     Near   the   sea,   however,    the 


324  WATER  SUPPLIES 

wells  may  and  often  do  yield  brackish  water.  Even  when 
some  considerable  distance  from  the  coast,  the  continued 
maintenance  of  a  low  level  in  the  well  may  result  in  the 
water  becoming  saline.  During  a  recent  exceptionally 
dry  season,  the  water  in  a  well  supplying  a  town  on  the 
coast  was  markedly  affected,  although  the  well  was  1J  miles 
from  the  shore.  The  chlorine,  which  is  normally  about 
3  grains  per  gallon,  gradually  increased,  until  a  maximum 
of  18  was  reached.  In  hilly  districts  water  is  most  likely 
to  be  found  in  the  lowest  portions  of  the  valleys.  Where 
the  water-bearing  stratum  is  covered  with  an  impervious 
one,  the  search  for  water  is  much  more  difficult,  but  a 
careful  study  of  the  local  geology,  to  ascertain  the  dip  of 
the  various  strata  and  the  thickness  of  those  lying  above 
the  water-bearing  rock,  will  usually  lead  to  reliable 
inferences  being  drawn.  This  is  not  invariably  the  case, 
however.  Thus  in  Essex  a  considerable  portion  of  the 
London  clay  is  capped  with  drifts  of  sand  and  gravel  and 
boulder  clay.  The  sand  and  gravel  lying  between  the 
London  and  the  boulder  clay  varies  in  thickness,  and  in 
some  places  is  entirely  absent,  and  it  is  often  impossible  to 
predict  whether,  by  sinking  at  any  particular  spot,  water 
will  be  found  or  not.  This  uncertainty  has  led  to  "  water- 
finders  "  being  employed,  and  as  there  is  a  pretty  general 
belief  in  the  "powers  of  the  hazel-twig  in  the  district,  it 
would  appear  as  if  the  finders  were  usually  successful. 
I  have  paid  some  attention  to  this  subject  lately,  and  find 
that  from  the  manner  in  which  the  hazel-twig  is  held,  by 
imperceptible  muscular  movements  it  can  be  made  to  rotate 
between  the  hands.  I  have  seen  the  water-finder  walk 
over  places  where  water  existed  in  abundance  without  the 
twig  indicating  its  proximity.  In  localities  which  have 
been  traversed  by  the  finder,  I  have  usually  found  that 
there  was  no  difficulty  in  indicating  where  water  could  be 
obtained  without  the  use  of  a  hazel-twig.  In  one  instance 
the  hazel-twig  gave  strong  indications  of  the  presence  of 


SOURCES  OF  WATER  SUPPLY,  ETC.  325 

water  at  a  point  at  which  I  was  certain  there  could  be  no 
water  within  300  feet,  since  the  soil  was  of  clay;  and  in 
that  particular  district  it  was  known  to  be  300  feet  in 
thickness.  The  owner  of  the  land,  however,  had  every 
confidence  in  the  water-finder  and  proceeded  to  dig  a  well. 
When  he  had  penetrated  the  clay  to  a  depth  of  about  100 
feet  and  found  no  indication  of  water,  his  confidence 
vanished,  and  the  work  was  abandoned.  A  gentleman  with 
whom  I  am  acquainted  contends  that  the  hazel-twig  in  his 
hands  gives  reliable  information.  He  believes  that  the 
presence  of  the  water  affects  him  personally,  and  the  twig 
through  him.  Twigs  of  other  trees  do  not  answer,  since 
they  do  not  possess  the  necessary  elasticity,  and  cannot  be 
made  to  rotate  nearly  so  readily  as  the  hazel.  He  has 
certainly,  recently,  been  able  to  indicate  the  presence  of 
water  in  unsuspected  places,  and  as  in  his  case  there  can 
be  no  suspicion  of  intentional  deception,  the  result  must 
either  be  due  to  accident  plus  unconscious  cerebration,  or 
to  some,  at  present,  inexplicable  influence  of  water  upon 
himself  or  the  twig.  A  recent  success  was  recounted  in  a 
letter  which  he  addressed  to  me  on  19th  May,  1894.  He 
says,  "  General  -  —  asked  me  if  I  would  give  my 
opinion  upon  the  practicability  of  finding  water  in  a  field 
facing  his  house.  I  went  over  and  marked  out  two  spots, 
and  at  each  of  these  places  digging  was  commenced,  and  at 
less  than  10  feet  from  the  surface  water  was  found.  ...  I 
should  add  that  some  time  since  an  engineer  made  experi- 
ments upon  the  same  ground  with  boring  apparatus,  but 
gave  it  as  his  opinion  that  within  the  area  no  water  was 
available."  According  to  the  geological  drift  map,  the 
parish  in  which  General  —  —  resides  is  partly  on  London 
clay,  partly  oil  gravel,  and  partly  on  boulder  clay  capping 
the  gravel,  and  it  would  seem  an  easy  matter  to  indicate 
almost  the  exact  limits  of  the  area  in  which  water  could 
be  found.  In  justice  to  my  friend,  however,  I  must  add 
that  he  knew  nothing  of  the  geology  of  the  district. 


326  WATER  SUPPLIES 

Certain  points  requiring  attention  in  selecting  the  site 
for  a  well  are  referred  to  in  Chapter  IV.,  and  the  possible 
effect  of  the  pollution  of  the  drainage  area  of  the  well,  and 
the  dimensions  of  this  area,  are  discussed  in  Chapter  XI. 
Before  works  of  any  magnitude  are  undertaken  for  utilising 
subsoil  water,  the  area  of  the  collecting  surface  should  be 
ascertained,  its  configuration,  etc.,  considered,  and  the 
depth  of  the  ground  water  and  the  extent  of  its  fluctuations 
determined.  The  less  the  fluctuation  the  more  likely  is  the 
supply  to  be  permanent,  and  the  less  the  liability  to  con- 
tamination. Rapid  fluctuations  usually  indicate  variation 
in  quality,  as  well  as  quantity,  of  the  available  water. 
Where  limited  amounts  only  are  required,  and  the  possi- 
bility of  finding  water  or  of  determining  the  quantity 
available  cannot  be  inferred,  from  the  absence  of  similar 
wells  in  the  vicinity,  trial  borings  or  sinkings  must  be 
made.  The  character  of  the  strata  penetrated  must  be 
noticed,  and  the  boring  continued  until  water  is  found  or 
an  impervious  stratum  reached.  Into  the  latter  it  is 
unnecessary  to  bore  unless  it  is  believed  to  be  of  but  slight 
thickness,  and  the  water  above  it  is  not  sufficiently 
abundant.  Thin  beds  of  clay  are  sometimes  found  in 
thick  gravel  drifts,  and  they  hold  up  a  certain  amount  of 
water,  which  is  obtainable  by  pumping.  When  the  clay 
is  penetrated,  the  gravel  beneath  may  not  be  fully  charged 
with  water,  in  which  case  that  found  above  will  run 
through  and  be  lost.  This  is  the  explanation  of  the 
mysterious  disappearance  of  water  from  certain  wells  which 
have  been  deepened  to  increase  the  supply  or  the  storage 
capacity.  Instead  of  the  supply  being  increased,  the 
limited  amount  previously  obtainable  has  been  lost,  and  the 
work  has  either  been  abandoned  or  an  attempt  made  to 
reach  the  water,  if  any,  held  in  the  lower  pervious  layer. 
Where  no  impervious  stratum  is  penetrated,  the  water 
when  reached  will  not  begin  to  rise  in  the  bore  hole,  or 


SOURCES  OF  WATER  SUPPLY,  ETC.  327 

only  to  a  very  slight  extent,  since  it  is  not  under  pressure. 
In  deep  wells,  which  will  be  considered  later,  as  soon  as 
the  water-bearing  rocks  are  reached,  the  water  begins  to 
rise,  more  or  less  rapidly,  and  may  even  overflow  at  the 
surface.  In  sinking  shallow  wells  the  trial  bore  must  be 
continued  until  the  depth  of  water  is  judged  sufficient.  By 
pumping  the  water  out  of  the  bore-  hole  and  noting  the 
time  required  for  it  to  again  ascend  to  its  former  level,  the 
abundance  or  otherwise  of  the  supply  may  be  judged, — the 
more  rapid  the  rise  the  greater  the  available  amount  of 
water.  The  yield  of  a  well  is  often  gauged  by  the  length  of 
time  required  for  it  to  fill  to  its  normal  level  after  being 
pumped  dry.  The  depth  of  water  and  the  diameter  of  the 
well  being  also  known,  the  yield  is  easily  calculated.  The 
result  so  obtained  is  always  too  low,  since  the  rapidity  with 
which  the  water  enters  varies  with  the  square  root  of  the 
head,  and  the  head  varies  with  the  difference  between  the 
level  of  the  subsoil  water  and  the  level  of  the  water  surface 
in  the  well.  A  more  accurate  result  therefore  is  obtainable 
by  starting  with  the  water  at  a  conveniently  low  level  (say 
at  half  the  usual  depth),  and  ascertaining  the  amount 
which  must  be  pumped  in  a  given  time  in  order  to  maintain 
it  at  this  level.  Such  experiments  only  indicate  the 
amount  available  at  that  particular  time,  but  if  made  after 
a  long  drought,  the  result  will  probably  indicate  the 
minimum  yield  of  the  well. 

Many  attempts  have  been  made  to  devise  formulae  for 
calculating  the  yield  of  water  from  wells  and  galleries  (vide 
Friihling's  Handbuch  der  Ingenieurwissenschafen).  Certain 
of  these  have  been  discussed  by  Fuertes  (Engineering 
Record,  vol.  xxxix.,  p.  28).  The  following  is  given  for 
calculating  the  yield  from  a  well  sunk  in  a  sandy  or 
gravelly  subsoil :  — 

Q  =  3-142X  (H2  -  /i2)  -f  natural  log.  (2K  -f-  d), 


328  WATER-SUPPLIES 

where 

Q  =  the  yield  in  gallons  per  second. 

H  =  depth,  of  water  in  well,  at  rest,  in  feet. 

R  =  radius  of  zone  of  depression. 

h  =  depth  after  pumping  in  feet. 

d   =  diameter  in  feet. 

X  =  PV,  where  P  —  the  percentage  of  void  in  the  sand  or  gravel 
(usually  30  to  40  per  cent.)  and  V  —  the  coefficient  of  velocity 
of  flow  of  water  in  the  gravel  =  about  -29  times  the  square 
of  the  effective  size  of  the  sand  or  gravel  in  millimetres. 

Obviously  there  are  so  many  factors  which  cannot  be 
determined  with  certainty  that  such  a  formula  can  have 
little  value. 

Where  the  limited  space  available  necessitates  the  well 
being  sunk  near  drains,  sewers,  cesspools,  or  other  similar 
possible  sources  of  pollution,  not  only  should  every  care  be 
taken  in  the  construction  of  the  well,  drains,  sewers  etc., 
to  avoid  contamination  of  the  water  supply,  but  the  risk 
should  be  reduced  to  a  minimum  by  sinking  the  well  in 
such  position  that  the  flow  of  the  subsoil  water  shall  be 
from  the  well  towards  the  drains,  and  not  from  the  drains 
towards  the  well.  In  villages  and  on  farms  the  ground 
water  is  usually  so  polluted  as  not  to  afford  a  safe  supply, 
however  carefully  constructed  the  well.  Good  water  can, 
in  some  cases,  be  obtained  at  a  little  distance  away  in 
the  direction  of  the  higher  ground-water  level.  This 
distance  will  vary  in  different  places  according  to  the 
porosity  of  the  subsoil,  slope  of  the  ground  water,  and 
amount  of  water  to  be  pumped.  Where  water  is  only 
pumped  in  small  quantities  at  a  time,  the  influence  of  the 
pumping  will  extend  but  a  short  distance  from  the  well; 
but  where  a  supply  tank  or  water  butt  has  to  be  filled  from 
time  to  time,  the  level  of  the  water  in  the  well  may  be 
considerably  depressed  and  the  drainage  area  be  greatly 
extended  (vide  Chap.  XVIII.).  According  to  the  per- 
meability of  the  subsoil,  the  area  capable  of  being  drained 


SOURCES  OF  WATER  SUPPLY,  ETC.  329 

by  the  well  will  vary  in  diameter  from  15  to  160  times  the 
normal  depth  of  water  in  the  well.  In  a  loamy  isoil  a 
distance  of  20  times  this  depth  may  be  sufficient  for  safety ; 
in  very  coarse  gravel  the  distance  should  be  150  times  the 
depth.  Where  the  slope  of  the  ground  water  is  steep 
there  might  be  safety  within  these  limits,  as  the  influence 
of  the  pumping  would  not  be  nearly  so  marked  at  the  side 
of  lower  water-level;  but  as  the  plane  of  saturation  is 
usually  nearly  horizontal  it  is  best  to  err  on  the  side  of 
safety  and  regard  it  always  as  such.  Whether  the  water 
should  be  obtained  by  sinking  an  ordinary  well  or  by 
driving  a  tube  well,  may  be  decided  after  considering  the 
advantages  and  disadvantages  and  relative  cost  of  the 
different  kinds  of  well  as  described  in  Chapter  XX.,  on 
"  Well  Construction." 

Where  springs  are  not  available,  and  water  is  not  obtain- 
able from  the  subsoil,  the  possibility  of  obtaining  a  supply 
from  a  deep  well  may  be  considered.  As  this  is  a  some- 
what serious  undertaking,  probably  attention  had  better  be 
directed  in  the  next  place  to  the  supply  which  can  be 
obtained  directly  from  the  rainfall.  It  is  agreed  that  about 
half  the  rain  which  falls  upon  the  roof  or  similar  impervious 
surface  during  the  whole  year  can  be  collected.  The  other 
half  is  lost  by  evaporation  and  by  waste  from  the  separators 
and  filters.  Why  should  not  this  rain  water  be  stored  and 
utilised?  Even  where  water  is  obtainable  for  drinking 
purposes  from  springs  or  wells,  it  may  be  so  hard  or  so 
limited  in  amount  that  it  is  desirable  to  collect  the  rain 
water  for  use  in  the  laundry  and  for  personal  ablution.  A 
fair-sized  mansion  has  often  a  roof  area  sufficiently  large 
to  collect  enough  rain  water  for  drinking,  cooking,  and 
general  domestic  purposes.  Assuming  the  area  covered 
by  the  roof  to  be  J  of  an  acre  (1,210  sq.  yards),  and  the 
minimum  rainfall  20  inches,  then  10  inches  of  this  may  be 
collected.  As  a  fall  of  1  inch  upon  an  acre  represents 
22,620  gallons,  10  inches  upon  £  of  an  acre  represents 


330  WATER  SUPPLIES 

56,550  gallons  for  the  year,  or  155  gallons  per  day,  a  supply 
which  would  suffice  for  ten  persons,  allowing  15  gallons  per 
head,  or  for  15  persons  at  10  gallons  per  head.  In  most 
parts  of  the  country  the  minimum  rainfall  reaches  25 
inches,  therefore  admitting  of  a  more  abundant  supply. 
Where  the  roof  surface  is  not  sufficiently  large  it  has  been 
proposed  to  prepare  a  plot  of  ground  for  the  purpose.  The 
best  method  of  collecting,  storing,  and  utilising  rain  water 
was  discussed  when  treating  of  rain  water  as  a  source  of 
supply  (Chap.  II.),  and  that  section  must  be  consulted  for 
further  details. 

Where  larger  quantities  of  water  are  required,  as  for 
villages  and  towns,  it  may  be  derived  from  the  rainfall  on 
natural  gathering  grounds,  from  the  subsoil,  from  springs, 
from  deep  wells,  or  from  streams.  Water  collected  in 
hilly  districts  from  uncultivated  surfaces,  forms,  as  we 
have  already  seen,  one  of  the  best  and  purest  supplies 
obtainable.  A  large  number  of  towns  in  this  country  are 
supplied  from  such  sources.  Unfortunately  in  several 
instances  the  amount  of  water  obtainable  in  the  area  of 
the  watersheds  has  been  over-estimated  the  result  being 
that  in  exceptionally  dry  seasons  something  like  a  water 
famine  has  occurred.  The  approximate  determination  of 
the  amount  of  water  which  can  be  collected  from  the 
surface  over  a  given,  area  is  one  of  the  most  difficult 
problems  in  water  engineering,  since  it  depends  upon  so 
many  factors,  some  of  which  (the  meteorological  conditions) 
are  so  variable  as  almost  to  defy  our  efforts  to  predicate 
their  possibilities.  Upon  these  meteorological  conditions, 
so  variable  in  themselves,  depend  in  a  very  great  measure 
two  other  factors — the  loss  by  evaporation  and  by  percola- 
tion. The  only  factors  which  are  uninfluenced  by  the 
weather  are  the  area,  configuration,  and  character  of  the 
collecting  surface.  The  6-inch  ordnance  maps  give  the 
contour  lines  or  lines  of  equal  altitude  drawn  at  every  25 
feet.  The  ridge  or  watershed  lines  are  also  marked,  and 


SOURCES  OF  WATER  SUPPLY,  ETC.  331 

from  these  the  ground  slopes  downwards  on  both  sides. 
These  lines  are  continuous,  save  on  the  side  which  forms 
the  natural  outlet  of  the  water  collected  in  the  enclosed 
area  of  gathering  ground,  technically  known  as  a  "  drainage 
area "  or  "  catchment  basin."  In  one  such  catchment 
basin,  branching  ridge  lines  may  form  two  or  more  second- 
ary drainage  areas.  The  area  from  which  the  water  is  to 
be  collected  may  either  be  ascertained  by  actual  measure- 
ment or  be  calculated  from  an  ordnance  map.  The 
configuration,  character  of  the  surface  and  of  the  subsoil, 
and  nature  and  amount  of  vegetation,  require  careful 
examination,  since  they  influence  greatly  not  only  the 
amount  of  rainfall  which  percolates,  but  also  the  amount  of 
loss  by  evaporation.  A  portion  of  the  water  which  pene- 
trates the  ground  in  one  part  of  the  area  may  reappear 
in  another  part  as  springs,  or  it  may  be  that  the  springs 
fed  by  the  ground  water  lie  entirely  outside  the  boundary 
of  the  watershed,  in  which  case  a  further  portion  of  the 
rainfall  escapes  collection. 

Where  the  hills  are  steepest,  the  rocks  hardest,  barest, 
and  most  impermeable,  the  loss  both  from  evaporation  and 
percolation  will  be  smallest.  The  more  permeable  the 
subsoil,  the  more  abundant  the  vegetation  and  the  less 
steep  the  slopes,  the  greater  will  be  the  loss  by  evaporation 
and  absorption.  Where  the  soil  is  peaty,  where  moss 
abounds  and  bogs  are  extensive,  much  water  is  retained; 
it  neither  runs  off  the  surface  nor  percolates  into  the 
subsoil,  but  is  slowly  lost  again  by  evaporation.  The  loss 
by  percolation  is  greatest  where  the  subsoil  is  very  porous — 
as  when  it  consists  of  sand  and  gravel — and  when  the 
outlet  for  the  ground  water  is  outside  the  collecting  area. 
However,  as  a  rule,  the  localities  selected  as  gathering 
grounds  for  water  supplies  have  but  a  small  proportion 
of  their  areas  covered  with  any  depth  of  permeable  subsoil, 
since  such  ground  is  objectionable,  not  only  because  of  the 
amount  of  water  which  it  permits  to  percolate,  but  because, 


332  WATER  SUPPLIES 

in  this  country  at  least,  it  would  be  cultivated  or  used  for 
pasturing  cattle,  and  would  therefore  tend  to  pollute  the 
water.  The  amount  of  water  which  may  be  lost  by  percola- 
tion has  been  referred  to  in  Chapter  IV.  Both  this  and 
the  loss  by  evaporation  are  affected  greatly  by  the  character 
of  the  rainfall.  If  the  rain  descends  in  frequent  slight 
showers,  the  whole  may  be  lost;  whereas  if  the  same 
amount  falls  in  a  few  heavy  downpours,  a  large  proportion 
will  run  off  the  surface  and  may  be  collected.  In  the  hilly 
districts  selected  as  gathering  grounds  the  rainfall  is  not 
only  usually  more  abundant  than  in  the  plains,  but  it 
descends  in  sharper,  heavier  showers.  As  the  water 
collected  from  any  given  area  would  otherwise  have  found 
its  way  into  some  stream  or  formed  the  natural  source  of 
such  stream,  the  problem  of  ascertaining  the  amount  of 
water  which  can  be  collected  is  frequently  the  same  as 
that  of  determining  the  amount  of  water  available  from 
a  stream.  These  we  have  already  considered  in  Chapter 
VII.,  under  the  heads  of  (a)  area  of  watershed,  (b)  the 
topography  and  geological  character  of  the  ground,  (c)  the 
average  rainfall  and  the  rainfall  during  a  consecutive 
series  of  dry  years,  (d)  the  seasonal  distribution  of  the 
rainfall,  (e)  the  amount  of  water  which  must  be  supplied 
for  "  compensation ';  purposes,  and  (f)  the  facilities  for 
obtaining  storage.  Based  upon  this  knowledge  engineers 
have  devised  formulae  for  estimating  the  probable  daily 
yield  of  a  catchment  area.  Dr.  Pole's  formula  is — 

Q  =  62 A  (f  Urn  -  E). 

In  this  equation  ~Rm  represents  the  average  rainfall  of  a 
long  series  of  years,  and  4  Rra  the  estimated  average  of  the 
three  driest  consecutive  years.  E  =  the  loss  of  rainfall  by 
evaporation,  percolation,  and  unavoidable  waste ;  and 
A  =  the  area  of  the  gathering  ground  in  acres.  As  1  inch 
of  rainfall  upon  1  acre  represents  22,620  gallons  of  water, 


SOURCES  OF  WATER  SUPPLY,  ETC.  333 

the  average  amount  of  water  which  can  be  collected  yearly 
during  the  three  driest  consecutive  years  would  be 

22,620 A  x  (4  Era  -  E). 

Since  22,620  divided  by  365  is  approximately  62,  Pole's 
formula  gives  the  mean  daily  yield  of  water  from  the 
catchment  area.  The  importance  of  the  factor  E  is  evident, 
and  it  is  to  the  fact  that  this  has  been  occasionally  under- 
estimated that  the  scarcity  of  water  in  certain  towns  during 
long-continued  periods  of  low  rainfall  is  chiefly  attributable. 
In  some  cases,  however,  the  fault  has  been  due  to  the 
reservoirs  not  having  been  sufficiently  capacious  to  allow 
of  the  accumulation  of  an  ample  reserve  to  tide  over  such 
periods  of  drought.  Under  any  circumstances  the  most 
capacious  reservoirs  may  become  filled,  and  rain  continue 
to  descend  and  pass  down  the  bye^wash  and  be  wasted. 
This  unavoidable  loss  Mr.  Hawksley  estimates  at  one-sixth 
of  the  rainfall.  The  loss  by  evaporation  and  percolation — 
which,  as  we  have  seen,  depends  upon  so  many  factors — is 
variously  estimated  by  engineers  who  have  studied  this 
subject.  Mr.  Hawksley  found  at  Sheffield  that  it  was 
nearly  15  inches,  "  although  the  ground  is  very  elevated, 
ascending  to  1,500  or  1,600  feet;  but  it  lies  rather  with  a 
southern  aspect,  and  the  ground  is  mossy,  and  a  good  deal 
of  water  is  held  superficially,  and  of  course  is  re-evaporated." 
In  this  country  the  loss  by  evaporation  and  percolation  is 
given  by  the  following  authorities  as  under :  — 

Mr.  T.  Hawkesley,  11  to  18  ins.     Average  14  ins. 
Dr.  Pole,  12  to  18  ins. 

Mr.  Humber,  9  to  19  ins.     Average  13  to  14  ins. 

Mr.  Bateman,  9  to  16  ins. 

Over  most  favourable  areas,  therefore,  the  loss  may  not 
exceed  9  inches,  whereas  over  the  most  unfavourable  ones 
which  are  likely  to  be  selected  as  gathering  grounds  it  may 
be  as  high  as  19  inches.  The  value  of  E  in  Dr.  Pole's  for- 


334  WATER  SUPPLIES 

mula,  therefore,  will  vary  from  — ~  +  9,  to  -  -  +  19,   -^ 

b  bo 

being  the  unavoidable  waste. 

The  amount  of  storage  necessary  to  render  the  required 
amount  of  water  available  during  the  longest  drought  varies 
considerably  in  different  places.  Where  the  rainfall  is 
heaviest  the  storage  necessary  is  least,  and  vice  versa.  Over 
the  western  half  of  this  country,  and  in  the  more  moun- 
tainous districts,  120  days'  storage  has  been  found  sufficient, 
but  in  the  eastern  counties  a  storage  for  300  days  might 
even  be  required.  In  such  districts,  however,  surface  water 
is  very  rarely  used  for  town  supplies.  There  are  few 
suitable  collecting  areas,  and  the  rainfall  is  too  low  and 
too  varied  in  its  seasonal  distribution  to  justify  any  attempt 
to  obtain  water  from  such  sources.  In  those  parts  of 
England  in  which  surface  water  can  be  rendered  available 
a  drought  extending  over  120  days,  or  a  succession  of 
droughts  corresponding  to  that  period,  must  be  so  rare 
as  to  be  phenomenal.  In  works  of  such  vast  importance 
all  errors  must  be  on  the  safe  side;  it  is  wisest,  therefore, 
to  make  provision  for  150  days'  drought  even  in  districts 
with  heavy  rainfalls,  and  in  less  favoured  districts  to 
provide  for  the  storage  of  200  days'  supply.  This  appears 
to  be  the  general  opinion  of  the  most  eminent  engineers. 
It  is  impossible  to  give  any  precise  rules  as  to  the  relation 
of  the  rainfall  to  the  amount  of  storage.  Mr.  Hawksley's 
well-known  formula  gives  results  which  confirm  the  opinion 
expressed  by  Dr.  Pole,  quoted  below.  Let  D  =--  the  number 
of  days'  storage  necessary,  and  F  =  the  mean  annual  rainfall 
of  a  long  series  of  years,  then  according  to  Hawksley 

D  =  1,000  -f  JF. 

With  a  rainfall  of  25  inches  this  formula  gives  200  as  the 
number  of  days'  storage  required ;  with  49  inches  143  days 
would  suffice.  Dr.  Pole  says  "  the  general  judgment  of 


SOURCES  OF  WATER  SUPPLY,  ETC.  335 

experienced  practitioners  appears  to  be  that  for  large 
rainfalls  a  storage  of  150  days  or  even  less  will  suffice,  but 
in  drier  districts  it  may  be  necessary  to  go  as  high  as  200 
days;  .  .  .  and  this  is  a  provision  which  may  reasonably 
be  borne."  The  extent  to  which  the  character  of  rain 
water  can  be  affected  by  the  surfaces  from  which  it  is 
collected  was  referred  to  in  Chapter  III. 

Subsoil  water  is  not  utilised  nearly  to  the  same  extent 
for  supplying  towns  as  surface  and  river  water,  whilst 
rural  communities  still  continue  to  be  supplied  chiefly  from 
this  source.  The  factors  upon  which  the  amount  of  water 
available  in  the  subsoil  can  be  estimated  have  already 
been  considered.  A  single  well  may  yield  sufficient  water 
for  a  large  village,  or  if  the  subsoil  be  chalk  or  sandstone 
and  admit  of  headings  being  driven  in  various  directions 
from  the  bottom  of  the  well,  one  well  may  even  supply  a 
town  of  moderate  size.  Where,  however,  two  or  more 
wells  are  required,  necessitating  a  corresponding  number 
of  pumping  stations,  a  considerably  increased  expenditure 
is  incurred.  A  village  may  sometimes  be  supplied  from 
a  single  well  in  a  patch  of  gravel,  but  usually  such  drifts  are 
not  sufficiently  extensive  or  thick  to  yield  a  constant  supply 
of  any  magnitude. 

The  chalk  formation  in  most  cases  contains  a  large  store 
of  excellent  water,  but  a  single  well,  even  with  headings, 
rarely  yields  enough  water  for  a  large  town.  The  drainage 
area  of  chalk  wells  cannot  be  estimated,  since  the  water 
exists  chiefly  in  and  travels  through  the  fissures,  and  but 
very  slightly,  if  at  all,  through  the  chalk  itself.  It  is 
evident  therefore  that  the  freedom  with  which  water 
percolates  through  a  chalk  subsoil  will  depend  upon  the 
abundance  and  size  of  these  fissures.  If  the  fissures  are 
numerous  and  large  the  drainage  area  may  be  very 
considerable.  The  well  referred  to  on  page  324  as  being 
affected  by  the  sea,  1J  miles  away,  is  sunk  in  the 
chalk.  Cases  are  also  recorded  in  which  impurities  have 


336  WATER  SUPPLIES 

been  found  to  enter  a  well  after  travelling  a  very  consider- 
able distance  through  such  fissures.  As  an  example  of  the 
amount  of  water  obtainable  from  wells  in  the  chalk,  the 
case  of  Croydon  may  be  cited.  The  old  waterworks  are 
close  to  the  town,  and  comprise  four  wells  sunk  in  the 
chalk  within  a  space  of  100  feet  square.  The  level  of  the 
water  in  the  wells  is  not  more  than  25  feet  from  the  surface, 
and  the  fissures  yielding  the  chief  portion  of  the  supply 
are  about  25  feet  lower.  Over  3,000,000  gallons  per  day 
have  been  pumped  from  them.  To  meet  the  increasing 
demands  of  the  town  a  new  well  was  opened  in  1888.  This 
is  sunk  200  feet,  all  in  the  chalk,  and  is  10  feet  in  diameter. 
Water  was  first  found  at  87  feet.  At  142  feet  from  the 
surface  and  below  headings  have  been  driven.  The  yield 
from  the  well  was  130,000  gallons  a  day,  but  the  first 
fissure  cut  by  a  heading  increased  the  daily  yield  to  600,000 
gallons,  and  when  the  yield  reached  2,500,000  gallons  a 
day  the  work  in  the  well  had  to  cease  through  the  inability 
of  the  two  24-inch  pumps  to  keep  the  water  down.  The 
total  length  of  the  headings  is  813  yards,  and  they  are 
generally  6  feet  high  and  4J  feet  wide.  The  storage 
capacity  of  these  and  the  lower  part  of  the  well  is  about 
half  a  million  gallons  (Borough  Engineer's  Report,,  1890). 
A  well  such  as  that  just  described  is  usually  spoken  of  as 
a  "  deep "  well,  although  sunk  entirely  in  one  pervious 
stratum.  The  chalk,  new  red  sandstone,  oolite,  and  green- 
sand  contain  vast  stores  of  water  of  excellent  quality 
accessible  over  very  large  areas  to  the  well-sinker  or  borer, 
but  it  must  not  be  forgotten  that  there  is  a  little  un- 
certainty in  searching  for  water  at  such  depths.  The 
most  experienced  geologists  are  sometimes  at  fault.  The 
variations  in  thickness  of  the  water-bearing  stratum  and  of 
the  strata  resting  upon  it,  the  possibility  of  hitherto 
unsuspected  faults  existing,  must  all  be  borne  in  mind. 
The  water,  also,  when  found,  may  be  quite  unsuitable  for 
domestic  purposes,  Thus  in  Essex  many  of  the  borings 


SOURCES  OF  WATER  SUPPLY,  ETC.  337 

piercing  the  London  clay  yield  a  water  containing  so  much 
sulphate  of  magnesia  as  to  be  aperient  in  property,  whilst 
others  have  yielded  a  water  so  brackish  as  to  be  useless. 
The  presence  of  beds  of  gypsum  and  of  rock  salt  in  the 
new  red  sandstone  must  not  be  forgotten,  the  former 
rendering  the  water  excesively  hard  and  the  latter  salty. 
At  Rugby  a  well  sunk  1,200  feet  yielded  only  brackish 
water,  and  at  Middlesborough  a  well  which  was  sunk  for 
obtaining  a  pure  water  yielded  so  strong  a  brine  that  salt 
is  extracted  from  it.  At  Wickham  Bishops,  Essex,  a 
boring  was  sunk  to  a  depth  of  about  1,000  feet  without 
water  being  found,  yet  everything  had  indicated  that 
an  abundance  of  water  would  be  reached  at  a  depth  of 
about  500  feet.  The  section  showed  that  there  existed  a 
previously  unknown  and  unsuspected  fault  crumpling  the 
London  clay  back  upon  itself,  so  that  this  stratum  had  to 
be  twice  pierced.  When  the  second  layer  had  been  pene- 
trated and  no  water  discovered  the  work  was  abandoned. 
In  other  places  the  fall  in  the  water-level  from  the  heavy 
continued  pumping  indicates  that  a  time  may  come  when 
such  supplies  will  fail,  and  unless  the  site  of  the  well  has 
been  carefully  chosen,  others  may  be  sunk  in  such  positions 
as  seriously  to  affect  the  supply. 

The  amount  of  water  obtainable  from  a  deep  well  in 
any  particular  locality  is  difficult  to  predict,  but  a  considera- 
tion of  the  conditions  bearing  thereupon,  referred  to  in 
Chapter  VI.,  will  assist  us  in  arriving  at  fairly  safe  con- 
clusions. The  information  contained  in  the  next  chapter, 
gathered  from  experienced  well-sinkers,  engineers,  geo- 
logists, and  others,  showing  the  actual  amounts  of  water 
which  have  been  obtained  from  various  underground 
sources  during  recent  years,  will  also  be  a  useful  guide. 

I  cannot  do  better  than  close  this  chapter  with  a 
quotation  from  an  address  by  Mr.  W.  WJiitaker,  F.R.S., 
recently  delivered  at  the  anniversary  meeting  of  the 
Geological  Society.  He  says :  "  Underground  water  is 

22 


338  WATER  SUPPLIES 

indeed  a  very  complicated  and  difficult  subject,  making 
strong  calls  on  our  reasoning  powers.  In  the  case  of 
springs  and  streams  we  are  dealing  with  facts,  things  that 
anyone  can  see;  but  in  the  case  of  underground  water  it 
is  a  very  different  matter;  we  have  to  make  inferences, 
and  though  our  inferences  may  be  warranted  by  all  that 
is  known  on  the  subject,  yet  it  is  seldom  that  we  can  speak 
with  certainty.  There  is,  therefore,  a  certain  charm  in 
questions  as  to  underground  water  that  is  wanting  in  the 
more  prosaic  subject  of  surface-waters. 

"  The  source  must  be  some  permeable  formation  of  good 
thickness  and  with  a  broad  outcrop,  as  the  quantity  of 
water  in  any  permeable  bed  must  depend  on  the  amount 
of  rain  that  falls  upon  it,  and  this  latter  greatly  on  the 
area  of  surface  exposed.  A  well,  therefore,  must  either 
be  upon  the  formation  that  is  to  be  the  source  of  supply 
or  upon  some  overlying  formation  through  which  it  can  be 
carried  to  the  water-bearing  stratum.  These  two  classes 
of  wells  sometimes  differ  greatly. 

"  In  the  first  case,  the  well  should  be  at  a  part  towards 
which  underground  water  flows :  away,  therefore,  from  an 
escarpment  or  ending-off  of  a  formation,  and  towards  the 
line  of  outcrop  or  where  the  next  overlying  formation 
comes  on.  It  should  also  be  in  low  ground,  as  a  rule,  so  as 
to  avoid  needless  depth.  In  the  second  case,  when  a  well 
has  to  be  taken  through  some  thickness  of  overlying  beds 
to  reach  the  water-bearing  bed,  different  conditions  some- 
times arise,  unless  the  well  is  near  the  outcrop  of  the 
water-bearing  formation. 

"  The  method  of  flow  of  water  through  the  rocks  must 
also  be  considered.  In  some,  this  is  mostly  through  the 
pores  or  the  spaces  between  the  particles  of  which  the  rock 
is  built  up ;  but  in  some  water-bearing  rocks  very  little 
passes  in  this  way.  Sometimes  the  planes  of  bedding  afford 
a  sort  of  channel,  but  at  others  these  are  closed  and  well 
packed  together.  Often  the  flow  is  along  joints,  or 


SOURCES  OF  WATER  SUPPLY,  ETC.  339 

structural  planes  that  have  been  formed  after  consolida- 
tion :  fault-planes  may  act  in  a  like  way. 

"  Though,  of  course,  every  opportunity  of  studying  the 
rocks  at  the  surface  should  be  taken,  it  must  not  be 
expected  that  they  will  show  the  same  features  when 
found  at  great  depths,  beneath  a  thick  mass  of  overlying 
beds.  Often  it  is  ascertained  that  beds  which  are  fairly 
open  in  sections  that  can  be  seen  have  their  fissures,  etc., 
more  or  less  closed  up  below  ground :  for  instance,  at 
Richmond,  where  the  Chalk  has  been  worked  horizontally 
under  a  great  depth  of  Tertiary  beds  (from  a  little  under 
to  a  little  over  300  feet),  a  very  great  length  of  gallery 
has  been  driven  with  the  result  of  cutting  comparatively 
few  fissures,  and  none  of  those  large,  so  that  but  little 
water  has  been  got ;  while  in  the  waterworks  for 
Southampton,  placed  on  the  Chalk  close  to  its  outcrop, 
so  that  there  was  no  occasion  to  sink  to  a  great  depth, 
a  very  much  less  amount  of  gallery  has  yielded  a  very  much 
larger  quantity  of  water. 

"  Moreover,  the  Kent  Company,  which  gives  our  largest 
supply  solely  from  wells,  has  done  comparatively  little  in 
the  way  of  driving  galleries,  but  has  depended  largely  on 
simple  wells  and  borings,  which  are  either  on  bare  Chalk 
or  where  there  is  no  great  thickness  of  other  beds  above 
the  Chalk. 

"  Again,  the  underground  condition  of  a  rock  may  vary 
greatly  in  places  near  together.  The  Brighton  Waterworks 
give  a  good  example  of  this;  for,  while  at  the  Lewes  Road 
Station  the  fissures  in  the  /Chalk  are  many  and  small, 
in  the  Goldstone  Bottom  Station,  not  far  to  the  west,  the 
fissures  are  mostly  large,  but  few.  Yet  the  two  stations 
are  at  about  the  same  horizon  in  the  Chalk,  and  there  is 
no  apparent  reason  for  this  difference  between  them.  A 
somewhat  similar  case  is  that  of  Croydon,  where  the  old 
works  in  the  town  give  a  much  larger  supply,  without 
galleries  (or  at  least  with  merely  short  connexions  between 


346  WATER  SUPPLIES 

the  wells),  than  that  which  is  got  from  the  new  works, 
but  little  lower  in  the  Chalk,  at  Addington,  where  there 
is  a  great  length  of  gallery. 

"  These  are  cited  as  illustrations  of  the  uncertainty  of 
underground  work,  an  uncertainty  with  which  many  of  my 
engineering  and  some  of  my  geological  friends  are  fairly 
familiar;  and  they  should  prepare  us  to  be  somewhat 
cautious  in  predicting,  at  all  events  before  we  know. 

"  Not  only  do  we  find  that  beds  pierced  at  great  depths 
often  have  a  character  different  from  that  which  they  put 
on  at  their  outcrop,  but  also  that  waters  found  at  great 
depths  often  vary  much  in  their  mineral  contents  from 
those  in  the  same  beds  much  nearer  the  surface.  A  well- 
known  case  of  this  sort  is  that  of  the  waters  in  the  Chalk 
under  London,  where  the  Chalk  is  thickly  covered  by 
Tertiary  beds,  those  waters  differing  greatly  from  the 
waters  in  the  bare  Chalk  northward  and  southward,  in  the 
increase  of  alkaline  salts  and  the  decrease  of  lime-salts. 

"  Other  like  cases  have  been  described  in  waters  from 
Jurassic  beds,  as  at  Swindon  anjd  at  Woodhall  Spa,  in 
both  of  which  a  large  amount  of  common  salt  occurs,  while 
in  the  latter  case  there  is  a  regular  mineral  water.  It  is 
found,  too,  that  waters  in  wells  from  the  sandy  beds  of  the 
Wealden  Series  often  contain  a  goodly  proportion  of  car- 
bonate of  soda. 

"  Such  matters,  and  the  occurrence  of  mineral  waters 
generally,  point  to  the  need  of  alliance  with  chemists,  and 
the  advantage  of  getting  full  analyses  of  well-waters,  which 
show  the  mineral  contents  and  do  not  merely  refer  to 
organic  purity  or  impurity.  With  this  help  we  may  be 
able  not  only  to  trace  the  origin  and  history  of  a  water, 
but  may  also  some  day  learn  something  of  those  slow, 
quiet,  unseen  changes  that  go  on  underground,  through 
the  agency  of  water  in  the  rocks :  a  subject  of  which,  I 
think,  we  know  little  as  yet,  at  all  events  in  this  country." 

It  is  advisable  in  all  cases  to  derive  the  whole  supply 


SOURCES  OF  WATER  SUPPLY,  ETC.  341 

required  from  one  and  the  same  source.  In  many  towns, 
especially  on  the  Continent,  water  is  derived  from  a  number 
of  different  sources.  This  may  have  been  due  to  the 
original  supply  proving  inadequate  on  account  of  the 
increase  in  population  and  the  increased  consumption  of 
water  required  by  a  higher  standard  of  cleanliness.  In 
Paris  a  dual  system  of  supply  has  been  adopted.  The  one 
furnishes  unfiltered  river  water,  and  is  used  for  municipal 
purposes  and  for  supplying  baths,  fountains,  etc.  The 
other  furnishes  a  purer  water,  derived  chiefly  from  springs 
in  the  valley  of  the  Vannes.  The  suggestion  to  adopt  such 
a  dual  system  elsewhere  has  not  been  favourably  received. 
Apart  from  the  enormous  additional  expense  necessitated 
by  a  duplicate  system  of  mains,  it  has  many  other  objection- 
able features.  At  Berlin  the  water  of  the  Spree,  after 
nitration,  supplies  a  portion  of  the  inhabitants,  whilst  others 
are  supplied  from  the  Tegeler  Lake.  Vienna  derives  water 
from  springs  in  the  Styrian  Alps  and  from  wells  sunk  in 
the  subsoil  on  the  banks  of  the  Schwarza.  The  water 
supply  to  Brussels  is  most  unsatisfactory,  and  is  derived 
from  the  subsoil,  from  the  Harre,  and  from  the  drainage 
of  the  Forests  of  Soignes  and  Cambre.  The  Leipzic  water- 
works present  several  peculiarities.  Water  from  the  Pleisse 
is  run  into  reservoirs,  and  the  water  niters  through  the 
natural  gravel  bottom,  and  is  collected  in  earthenware 
pipes,  with  open  joints,  which  are  laid  in  the  subsoil  for 
this  purpose.  This  supply  is  supplemented  by  the  yield 
from  five  groups  of  Artesian  wells.  The  water  supplying 
Stockholm  is  derived  in  part  from  a  lake  and  in  part  from 
the  subsoil,  almost  exclusively  from  the  latter  during  the 
winter  months.  Interesting  details  of  these  and  other 
works  are  given  by  Palmberg  and  Newsholme  in  their 
Treatise  on  Public  Health  and  its  Applications  in  different 
European  Countries, 


CHAPTER  XVIII. 

THE  PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES. 

NOTWITHSTANDING  the  immense  progress  which  has  been 
made  in  this  country  in  recent  years  in  practical  sanitation 
and  in  sanitary  administration,  outbreaks  of  preventable 
disease  due  to  the  pollution  of  water-supplies  have  been 
all  too  frequent.  Common  sense  suggests  that  if  it  is 
desired  to  obtain  a  pure  supply  of  water,  a  source  should 
be  selected,  removed  as  far  as  possible  from  any  contaminat- 
ing agencies,  and  that  every  reasonable  precaution  which 
science  or  experience  can  suggest  should  be  taken  to 
prevent  either  wilful  or  accidental  pollution.  At  present 
only  underground  sources  are  being  considered,  waters 
derived  from  streams  and  rivers  being  discussed  later. 
Both,  of.  course,  are  derived  from  the  same  source— the 
rainfall — but  the  modes  by  which  they  may  become  polluted 
are  somewhat  different,  and  the  precautions  which  require 
to  be  taken  to  prevent  pollution  are  also  different.  Whilst 
streams  are  fed  in  a  great  measure  by  the  rainfall  which 
has  not  penetrated  the  ground,  but  merely  run  over  the 
surface,  the  subsoil  water  and  the  water  in  the  deeper 
pervious  strata  is  derived  entirely  from  the  rainfall  which 
has  been  absorbed  by  the  soil,  and  which  has  percolated 
to  the  depth  at  which  it  is  found.  It  is  obvious,  therefore, 
that  the  collecting  areas  in  the  two-  cases  must  be  very 
different  in  character.  The  one  requires  an  impervious 
or  but  slightly  pervious  strata,  the  other  a  pervious  surface. 
The  pervious  surface  will  almost  certainly,  in  this  country 

(342) 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      343 

at  least,  be  tilled  for  agriculture,  and  more  or  less  highly 
manured.  Such  manurial  matters  as  are  soluble  will  be 
dissolved  by  the  rainfall,  and  the  finer  particulate  matter 
will  become  suspended  in  the  water.  All  underground 
waters,  therefore,  are  more  or  less  liable  to  pollution  at 
what  may  be  regarded  as  their  source,  the  rain  which  has 
fallen  upon  the  pervious  ground,  and  if  they  did  not 
afterwards  undergo  some  efficient  process  of  purification, 
underground  sources  would  have  to  be  abandoned.  In 
shallow  wells  constructed  near  houses  the  water  is  fre- 
quently very  impure,  and  is  notoriously  liable  to  specific 
pollution,  a  large  proportion  of  the  outbreaks  of  typhoid 
fever  recorded  in  this  country  being  due  to  the  use  of 
shallow  well  water.  Too  great  proximity  to  houses  and 
sewers  can  be  avoided,  but  that  no  house  drainage  or  human 
excreta  shall  be  placed  upon  the  gathering  ground  is  a 
matter  beyond  control.  Circumstances,  therefore,  compel 
the  use  of  water  liable  to  specific  pollution,  and  the  point 
for  consideration  therefore  is,  Can  this  water  undergo 
naturally  such  a  process  of  filtration  as  will  render  it  for 
all  practical  purposes  absolutely  safe  for  domestic  use? 

The  word  "  filtration  "  rather  than  purification  is  here 
used  intentionally,  because  the  specific  material  which  has 
to  be  removed  from  the  water  is  not  something  in  solution, 
but  particulate  matter  in  suspension,  and  as  has  been 
already  remarked  this  particulate  matter,  though  of  ex- 
tremely minute  dimensions,  is  capable  of  being  removed 
by  filtration.  This  particulate  matter  also  must  be  living, 
and  there  is  every  reason  to  believe  that  neither  the 
typhoid  nor  the  cholera  organism  can  survive  more  than  a 
limited  time  in  water,  especially  if  the  water  be  free  from 
polluting  matter,  and  that  they  will  not  live  long  in 
unpolluted  soil.  If  therefore  the  subsoil  can  so  filter  the 
water  passing  through  it  as  to  remove  these  living  organ- 
isms, or  if  these  organisms  in  traversing  the  subsoil  find 
themselves  in  such  an  unfavourable  environment  that 


344 


WATER  SUPPLIES 


life  is  impossible,  it  is  obvious  that  water  which  has 
percolated  through  a  sufficient  depth  or  flowed  longi- 
tudinally through  a  sufficient  thickness  of  the  subsoil,  will 
contain  none  of  the  specific  organisms,  and  can  be  used 
without  risk  of  producing  these  specific  diseases.  The 
water  which  falls  upon  the  surface  of  a  porous  soil  tends 
in  a  downward  direction  until  it  reaches  the  level  of  the 
subsoil  water.  It  then  takes  on  a  lateral  direction,  flowing 
through  the  interstices  in  the  stratum  towards  its  natural 
outlet,  whether  this  be  a  well-defined  spring,  a  flowing 
stream  or  the  ocean.  During  its  progress  the  organic  im- 
purities at  first  absorbed  are  more  or  less  completely 
removed.  The  organic  matter  in  solution  becomes  oxidised 
or  "  burnt  "  up,  and  we  find  the  ashes,  carbonates,  nitrates, 
sulphates  and  phosphates  only  in  the  water  if  the  oxidation 
has  been  complete.  The  living  organisms  are  more  or 
less  completely  removed,  in  part  by  the  natural  filtration 
and  in  part  probably  by  other  agencies  which  cause  their 
destruction.  A  water  originally  very  impure,  and  specifically 
polluted,  may  become  hygienically  pure  and  wholesome 
by  passing  through  a  sufficient  thickness  of  subsoil.  The 
upper  portions  of  the  soil,  to  which  air  has  comparatively 
free  access,  especially  if  covered  with  vegetation,  have  the 
most  powerful  action.  Nitrifying  organisms  abound,  and 
convert  the  dead  organic  matter  into  simpler  inorganic 
compounds,  and  the  living  organisms  are  more  or  less 
completely  filtered  out.  So  complete  may  be  this  purifica- 
tion that  from  properly  constructed  deep  wells  water  may 
often  be  obtained  almost,  if  not  absolutely,  free  from 
organic  matter,  living  or  dead.  These  natural  purifying 
processes  have  not  as  yet  been  sufficiently  studied,  but 
sufficient  is  known  to  enable  fairly  safe  conclusions  to  be 
drawn  as  to  the  means  which  must  be  adopted  to  obtain 
a  pure  water  supply  from  underground  sources. 

Before  referring   more  fully   to   these  natural   processes 
of  purification,   the  brief  consideration   of   the   sources   of 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      345 

underground  water  supplies  known  to  have  caused  out- 
breaks of  typhoid  fever  or  cholera  will  prove  instructive. 
The  late  Dr.  Ernest  Hart  prepared  a  historic  summary 
of  local  outbreaks  of  typhoid  fever  in  Great  Britain  and 
Ireland,  occurring  between  1858-1893,  due  to  specifically 
polluted  water,  which  summary  contains  a  tabulated 
analysis  of  205  epidemics.  Considering  only  those  due 
to  the  use  of  subsoil  water — and  these  form  about  two- 
thirds  of  the  whole — it  will  be  found  that  nearly  all  were 
due  to  the  use  of  water  derived  from  shallow  wells  situated 
within  a  very  few  ieet  of  defective  cesspits,  leaky  cesspools 
or  sewers.  Take  two  examples  selected  at  random  from 
the  more  recent  outbreaks.  "  Well  sunk  in  gravel  with 
strong  clay  watertight  bottom.  Drain  ran  close  to  the 
well  used  by  the  first  patient  and  leaked  into  the  well. 
Evacuations  thrown  into  the  common  ashpit  and  adjacent 
sink.  All  wrells  in  the  locality  open  to  the  same  water 
movement  and  sunk  in  soil  charged  to  overflowing  with 
impurities  of  every  kind."  Or  again,  referring  to  a  much 
more  serious  epidemic,  "  Water  supply  obtained  from  three 
wells  with  three  headings,  two  headings  serving  as  connect- 
ing tunnels  between  the  three  wells.  The  heading  driven 
from  one  well  only  in  the  early  part  of  the  year,  a  large 
fissure  struck,  the  inrush  of  water  being  so  great  that  the 
men  in  the  tunnel  had  to  fly  for  their  lives.  Soil  overlying 
the  chalk  in  which  were  sunk  these  wells  liable  to  sustained 
pollution  by  sewage."  With  each  outbreak  the  same 
story  is  related.  Wells  sunk  in  a  sewage-polluted  subsoil, 
near  drains,  sewers,  or  cesspools,  or  in  a  fissured  stratum, 
the  fissures  of  which  communicated  more  or  less  directly 
with  the  source  of  pollution.  In  no  instance  is  there  a 
record  of  an  outbreak  being  produced  by  water  derived 
from  a  well  sunk  in  a  carefully  selected  site,  and  in  which 
the  simplest  precautions  had  been  taken  to  prevent  pollu- 
tion. The  wells  were  so  situated  that  anyone  possessing  a 
smattering  of  knowledge  of  sanitary  matters  would  have 


346  WATER  SUPPLIES 

said  that  sooner  or  later  they  would  become  specifically 
infected  and  an  outbreak  of  disease  result.  If  the  various 
reports  upon  outbreaks  of  cholera  are  consulted  the  same 
conditions  are  found,  the  absence  of  all  precautions,  and  the 
source  of  fjecal  contamination  easily  traceable.  The 
evidence  gained  from  dearly  bought  experience  is  in  each 
series  of  cases  the  same. 

Professor  Pettenkofer  has  long  taught  that  a  polluted 
soil  is  the  best  nidus  for  the  propagation  of  the  typhoid 
bacillus,  and  Dr.  Hauser,  of  Madrid,  expresses  similar 
views  with  reference  to  the  cholera  bacillus.  That  the  soil 
is  the  natural  nidus  of  these  disease-producing  organisms 
outside  the  human  body  is  now  generally  conceded,  but 
there  are  soils  and  soils,  and  to  explain  all  the  facts  it  is 
necessary  to  assume  that  only  certain  soils  are  favourable, 
and  that  in  others  the  conditions  are  so  unfavourable  that 
multiplication  therein  is  impossible.  The  favourable  soils 
appear  to  be  those  which  contain  organic  matter,  especially 
of  animal  origin,  sewage  and  excremental  matters  generally. 
The  unfavourable  soils  are  those  which  contain  least  organic 
matter,  and  more  especially  are  free  from  sewage  pollution. 
These,  of  course,  are  not  the  only  factors,  but  they  are  the 
only  ones  bearing  directly  upon  the  subject  under  con- 
sideration. 

In  an  investigation  made  on  behalf  of  the  Local  Govern- 
ment Board,  a  preliminary  report  of  which  has  recently 
been  published,  Dr.  Sidney  Martin  found  that  the  typhoid 
bacillus  and  the  colon  bacillus  (an  organism  allied  to  the 
typhoid  bacillus,  and  found  in  large  numbers  in  all  sewage 
matters)  rapidly  increased  in  the  sewage-sodden  soil  from 
Chichester,  whereas  in  virgin  soil  under  similar  conditions 
they  very  speedily  died  out.  When  black  mould  containing 
organic  matter  was  used,  both  bacilli  retained  their  vitality 
for  a  considerable  period,  whereas  in  none  of  the  experi- 
ments with  virgin  soil  did  any  growth  whatever  occur. 
Still  more  recently  Dr.  Robertson  has  published  the  results 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      347 

of  a  series  of  experiments  conducted  at  St.  Helens,  of  which 
town  he  was  the  Medical  Officer  of  Health.  The  results 
were  very  suggestive,  and  proved  that  the  typhoid  bacillus 
was  capable  of  multiplying  rapidly  under  certain  conditions. 
He  inoculated  a  large  quantity  of  broth  with  the  typhoid  ' 
bacillus,  and  with  this  infected  various  patches  of  ground. 
Upon  the  patches  which  were  manured  with  dilute 
organic  solutions  the  typhoid  bacillus  throve  lustily,  upon 
the  patches  not  so  treated  they  languished  and  died. 
A  very  significant  fact  is  also  recorded  by  Dr.  Robertson. 
When  the  ground  was  infected  18  inches  beneath  the 
surface  the  bacilli  grew  to  the  surface;  when  the  surface 
was  inoculated  they  only  grew  downwards  to  a  depth  of 
3  inches.  This  inability  of  the  rainfall  to  carry  the  organ- 
isms deeper  into  the  soil,  and  the  fact  of  the  deep  cultures 
growing  upwards  to  the  surface  confirm  the  view  that  it 
is  only  in  the  surface  soil  that  any  active  propagation 
can  take  place.  At  a  little  depth  below  the  surface  the 
conditions  become  so  unfavourable  that  any  growth  which 
may  take  place  is  in  an  upward  direction ;  at  a  greater 
depth  probably  no  growth  whatever  would  occur,  and  the 
organisms  would  quickly  die. 

Abba,  Orlandi,  and  Rondelli  *  have  recently  conducted 
certain  investigations  at  Turin  to  test  the  filtering  power 
of  the  subsoil  from  which  the  water  supply  to  the  city 
is  obtained.  For  this  purpose  they  used  diluted  broth 
cultures  of  Bacillus  prodigiosus.  They  found  that  this 
bacillus  penetrated  to  a  depth  of  3  metres  (about  10  feet) 
but  did  not  pass  into  the  ground  water  save  after  heavy 
and  persistent  rains. 

Whatever  may  be  the  explanation,  there  is  much  evidence 
to  prove  that  at  a  very  limited  depth  beneath  the  surface 
of  a  compact  porous  soil  the  subsoil  and  the  subsoil  water 
are  practically  sterile.  Koch  appears  to  attribute  this  to 

*  Zeitschrift  fur  Hygiene,  vol.  xxxi.,  1899,  p.  66.  Abstracted  by  Dr. 
McWeeney  in  Journal  of  State  Medicine,  vol.  viii.,  p.  47. 


348  WATER  SUPPLIES 

a  mere  process  of  natural  filtration,  since  in  his  paper  on 
"  Water  Filtration  and  Cholera,"  he  says,  "  Rain  water 
when  it  sinks  into  the  ground  and  ultimately  becomes  sub- 
soil water  passes  through  far  thicker  layers  and  with  far 
less  rapidity  than  river  water  when  passing  by  artificial 
filtration  through  sand  filters.  If  the  sand  is  only  suf- 
ficiently granulated  we  have  in  soil  filtration  a  much  more 
perfect  process  than  is  at  our  disposal  in  artificial  filtration. 
This  is  confirmed  by  the  investigations  of  C.  Fraenkel, 
who  has  shown  that  subsoil  water,  even  in  a  soil  which  has 
been  much  and  for  a  long  period  contaminated,  as  in  the 
case  of  Berlin,  is  quite  free  from  germs.  In  other  places 
the  same  results  have  followed  from  investigations  made  on 
this  point."  Quite  recently  I  have  confirmed  these 
observations  in  some  experiments  made  with  sand  taken 
from  various  depths  beneath  the  surface.  Up  to  a  depth 
of  about  4  feet  organisms  were  present,  but  at  4  feet  they 
appeared  to  be  anaerobic,  below  5  feet  I  could  not  find 
any  organisms  whatever. 

The  bacterial  purity  of  subsoil  water,  however,  is  not 
altogether  due  to  the  efficiency  of  the  natural  process  of 
filtration.  No  doubt  the  conditions  which  obtain  under- 
ground are  very  unfavourable  to  the  growth  of  many 
organisms,  and  there  is  abundance  of  evidence  to  prove 
that  the  bacteria  producing  typhoid  fever  and  cholera  are 
in  a  more  or  less  unfavourable  environment  when  in  water, 
and  can  only  survive  for  a  very  limited  period.  Most  of 
the  experiments  recorded,  having  reference  to  the  vitality 
of  the  typhoid  bacillus  in  water,  have  little  or  no  bearing 
upon  the  subject  under  consideration,  the  conditions  under 
which  they  were  conducted  being  so  different  from  those 
which  obtain  in  nature.  Others  again  are  unreliable  on 
account  of  fallacies  underlying  the  methods  of  examination 
adopted.  This  question  of  survival  is  a  point  of  the 
utmost  importance.  Again,  as  far  as  is  known,  typhoid 
fever  and  cholera  are  exclusively  human  affections,  and 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      349 

there  is  no  evidence  to  prove,  nor  are  there  any  recorded 
facts  which  necessitate  the  assumption,  that  cattle  of  any 
kind  suffer  from  these  specific  diseases  and  discharge  ex- 
cremental  matter  capable  of  specifically  infecting  the  soil. 

The  remarks  already  made  with  reference  to  soil  pollution 
apply  equally  to  those  cases  in  which  the  source  of  pollu- 
tion is  beneath  the  surface,  as  to  those  in  which  the  filth 
is  deposited  upon  the  surface.  Fortunately  all  sewage 
contains  microbes  which,  during  their  growth  and  develop- 
ment, tend  to  break  down  the  dead  organic  matter  upon 
which  they  subsist,  into  simpler  and  more  stable  forms, 
that  is  to  say,  under  suitable  conditions  sewage  will  purify 
itself.  This  fact,  which  is  only  just  beginning  to  be 
recognised,  is  being  taken  advantage  of  for  the  purification 
of  sewage,  in  the  so-called  bacterial  filters  of  Dibdin,  Ducat 
and  others.  Everyone  who  has  had  to  watch  the  process 
of  excavation  in  the  vicinity  of  defective  sewers  and  cess- 
pools has  observed  that  there  is  little  or  no  evidence  of 
pollution  in  the  subsoil,  except  in  the  immediate  vicinity 
of  the  defects  which  permitted  the  pollution.  This 
purifying  action  of  the  subsoil  is  easily  demonstrated  on  any 
fairly  large  patch  of  drift  upon  which  a  village  stands. 
On  the  side  furthest  from  the  natural  outlet  of  the  water, 
the  wells  yield  what  may  be  called  the  normal  water  of  the 
patch,  containing  very  little  organic  matter  and  only 
comparatively  small  quantities  of  chlorides  and  nitrates. 
Within  the  village  many  of  the  wells  will  be  found  to  be 
highly  polluted,  but  almost  invariably  some  will  be  found 
which,  either  on  account  of  their  better  construction  or 
their  greater  distance  from  a  source  of  pollution,  are  also 
practically  free  from  organic  matter,  though  containing 
large  quantities  of  chlorides  and  nitrates.  On  the  side 
nearest  the  natural  water  outlet  the  same  condition  is 
found,  the  only  evidence  of  the  previous  pollution  being 
the  ashes  of  the  consumed  organic  matter.  Besides  the 
chemical  change  the  natural  process  of  filtration  has  taken 


350  WATER  SUPPLIES 

place.  Subsoil  water  travels  horizontally  at  a  very  slow 
rate  indeed,  compared  with  the  rate  at  which  water  is  passed 
through  artificial  filter-beds,  and  it  is  practically  impossible 
for  particulate  matter,  living  or  dead,  to  be  carried  any 
distance  by  the  current. 

In  certain  places,  however,  the  subsoil  water  may  flow 
with  an  appreciable  velocity,  and  in  channels  more  or  less 
defined.  The  reason  for  this  can  easily  be  understood. 
Suppose  that  a  valley  scooped  out  of  some  impervious 
stratum,  such  as  the  London  clay,  were  to  become  ob- 
literated by  being  filled  with  sand  and  gravel.  A  portion 
of  the  rainfall  upon  the  now  exposed  area  would  percolate 
into  the  sand  and  tend  towards  the  centre  of  the  original 
valley,  finally  makinjg  its  way  to  the  lowest  point.  The 
greatest  flow  would  be  along  the  bottom  of  the  valley,  and 
doubtless  here  in  the  course  of  time,  it  might  be  ages,  the 
resistance  would  diminish  from  the  washing  away  of  the 
finer  particles,  and  after  reaching  this  channel,  possibly 
no  further  purification  or  filtration  would  take  place. 
Herein  lies  one  of  the  dangers  of  the  use  of  subsoil  springs. 
These  springs  are  but  the  natural  outlet  of  the  subsoil 
water,  and  impurities  entering  the  subsoil  immediately 
over  the  line  of  flow  are  much  more  likely  to  be  dangerous 
than  impurities  entering  elsewhere.  The  nearer  the  spring 
or  the  line  of  flow  the  greater  the  danger  and  the  greater 
the  need  for  protection.  In  the  neighbourhood  of  rivers 
also,  there  is  often  a  considerable  flow  of  water  in  the 
subsoil,  rendering  it  necessary  to  direct  particular  attention 
to  the  protection  of  the  ground  above  the  point  at  which 
water  is  being  abstracted. 

So  far  it  has  been  taken  for  granted  that  a  subsoil  of 
uniformly  compact  consistence  was  being  considered,  such 
as  deposits  of  drift,  beds  of  sandstone,  etc. ;  but  there  are 
other  pervious  water-bearing  strata,  of  which  chalk  is  the 
best  example,  which  are  not  uniform,  but  full  of  fissures. 
It  is  obvious  that  water  which  has  once  entered  these  open 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      351 

fissures  will  undergo  little  further  chemical  nitration,  and 
that  polluting  matters  may  be  carried  great  distances 
thereiyi.  Here  again,  however,  the  upper  surface  of  such 
a  stratum  is  almost  certain  to  be  fairly  compact,  the  fissures 
being  obliterated  by  the  surface  soil,  and  water  passing 
through  will  be  more  or  less  completely  purified.  In 
travelling  along  the  open  fissures,  the  velocity  of  flow  (save 
in  the  immediate  vicinity  of  the  natural  or  artificial  outlet) 
must  be  very  slow,  giving  time  for  sedimentary  matters 
to  be  deposited,  and  for  such  organisms  as  the  typhoid  and 
cholera  bacilli  to  die  and  be  carried  down  therewith. 
Water  collected  from  deep  wells  in  fissured  strata,  at  points 
many  miles  removed  from  the  exposed  collecting  area,  is 
usually  found  to  be  particularly  free  from  organic  matter, 
and  to  contain  few  if  any  bacteria;  but  the  freedom  with 
which  water  can  traverse  these  fissures  has  too  often  been 
painfully  obvious  in  counties  near  the  coast,  inasmuch 
as  wells — sunk  at  great  cost — have  had  to  be  abandoned 
on  account  of  the  rapid  infiltration  of  sea  water.  By 
continuous  pumping,  the  water  level  had  been  so  depressed 
that  a  return  current  from  the  sea  was  set  up.  The  area 
which  may  be  directly  drained  by  a  well  in  a  fissured 
stratum  is  therefore  enormously  larger  than  that  which 
can  be  affected  in  a  uniform  porous  stratum. 

To  ensure  a  continuous  supply  of  hygienically  pure  water 
from  an  underground  source,  many  points  have  to  be 
taken  into  consideration;  and  no  general  rules  can  be  laid 
down  applicable  to  all  circumstances.  There  are  many 
wells  used  for  large  public  supplies  which  ought  to  be 
abandoned,  on  account  of  their  proximity  to  groups  of 
dwelling  houses.  In  many  cases  these  houses  have  been 
erected  since  the  works  were  established;  too  small  an 
area  of  land  was  acquired  in  the  first  instance,  and  the 
mistake  cannot  now  be  rectified.  There  should  be  an  area 
of  ground  around  each  such  well  under  the  absolute  control 
of  the  purveyors  of  the  water.  The  well  should  be  con- 


352  WATER  SUPPLIES 

structed  so  as  to  admit  water  only  at  the  lowest  point 
possible.  If  the  pumping  machinery  is  in  or  over  the  well 
care  should  be  taken  to  prevent  dirt  of  any  kind,  especially 
from  the  workmen's  boots,  reaching  the  water.  The  im- 
mediate vicinity  of  the  well  should  either  be  uncultivated 
or  laid  down  to  grass,  but  not  fed.  An  outer  ring  should 
be  similarly  laid  down,  but  cattle  might  be  permitted  to 
feed  thereon.  These  two  rings  may  be  called  the  inner  and 
outer  protective  areas,  and  the  inner  ring  should  be  so 
enclosed  that  no  one  can  enter  "  except  on  business."  The 
area  of  this  inner  ring  should  be,  at  least,  as  large  as  the 
area  of  the  cone  of  depression  produced  by  the  pumping. 
For  example,  suppose  that  45,000  gallons  are  being  pumped 
per  day  from  a  sandy  subsoil,  and  that  the  depression  of 
the  water  level  in  the  well  caused  by  the  pumping  is  9  feet. 
Each  cubic  foot  of  the  saturated  sand  would  yield  about 
H  gallons  of  water.  To  yield  the  45,000  gallons  therefore, 
30,000  cubic  feet  of  the  subsoil  would  be  drained.  The 
cone  of  depression  having  a  depth  of  9  feet,  the  area  of  its 
base  would  be  10,000  square  feet,  representing  a  circle  with 
a  radius  of  57  feet,  the  well  being  at  the  centre.  The  cone, 
however,  has  not  straight  sides,  and  to  be  perfectly  safe 
therefore  a  radius  of  30  yards  had  better  be  allowed.  The 
outer  protective  area  should  have  a  radius  double  or  treble 
that  of  the  inner  area. 

In  a  uniform  subsoil  the  rapidity  with  which  the  water 
travels  toward  the  well  decreases  as  the  square  of  the 
distance.  If  within  3  feet  of  the  well  the  movement  of 
the  water  is  at  the  rate  of  1  foot  per  second,  at  30  feet  the 
movement  of  the  water  will  only  be  at  one  one-hundredth 
of  that,  or  1  foot  in  100  seconds,  and  at  30  yards  the  rate 
will  be  1  foot  in  900  seconds.  Therefore,  at  a  certain 
distance  away  from  the  well  the  movement  of  the  water 
is  so  slow  that  perfect  nitration  is  secured.  That  is  to  say, 
the  water  passes  through  the  subsoil  very  much  more 
slowly  than  it  passes  through  the  sand  in  an  ordinarily 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      353 

constructed  filter,  and  for  that  reason  the  protective  area 
need  not  extend,  assuming  my  views  to  be  correct,  more 
than  a  limited  distance  round  the  well. 

I  am  strongly  of  opinion  that  this  protective  area 
should  in  future  always  be  insisted  upon,  but  its  extent 
may  have  to  be  denned  in  each  individual  case.  The 
conditions  vary  so  greatly  that  no  general  rule  can  be 
adopted.  In  deciding,  many  factors  have  to  be  taken  into 
account :  the  contour  of  the  ground,  the  depth  and  nature 
of  the  subsoil,  the  height  of  the  subsoil  water  and  the  range 
of  its  fluctuations,  the  possible  sources  of  pollution,  the 
amount  of  water  to  be  abstracted,  etc.  The  direction  of 
the  flow  of  the  subsoil  water  must  also  be  considered,  since 
polluting  matter  entering  the  soil  on  the  side  upon  which 
the  water  is  flowing  towards  the  well  is  naturally  more 
dangerous  than  if  it  enters  on  the  side  where  the  flow  is 
from  the  well.  Naturally  also  a  much  larger  protective 
area  will  be  required  where  the  subsoil  water  is  only  a  few 
feet  from  the  surface,  than  where  it  is  15  to  20  or  more 
feet  below.  Where  the  underground  water  is  known  to  be 
flowing  in  a  fairly  well  defined  underground  channel,  the 
protective  areas  had  better  be  elliptical,  the  longer  axis 
having  the  direction  of  flow,  the  well  being  on  this  axis 
but  nearer  the  end  towards  which  the  water  is  flowing. 
This  elliptical  protective  area  will  in  most  cases  be  desirable 
for  springs,  for  reasons  which  are  so  obvious  as  not  to 
require  enumeration. 

In  many  instances  the  protection  of  the  water  is  rendered 
more  difficult,  and  the  problem  becomes  more  complex, 
from  adits  or  collecting  channels  being  driven  or  trenched 
in  one  or  more  directions  in  order  to  increase  the  available 
supply  of  water.  These  drains  should  be  laid  as  low  as 
possible.  Only  under  exceptional  circumstances  should 
they  be  less  than  10  feet  deep,  and  the  trenches  should  be 
very  carefully  filled  in  and  tightly  rammed.  The  whole 

23 


354  WATER  SUPPLIES 

of   this   trenching   should   be   well   within   the   inner   pro- 
tective area. 

Where  the  subsoil  is  fissured  the  danger  of  pollution  is 
greater  and  protection  more  difficult,  since  the  source  of 
the  danger  may  be  concealed  and  may  almost  defy  detec- 
tion. A  striking  example  of  these  dangers  was  furnished 
by  the  outbreak  of  typhoid  fever  at  New  Herrington, 
Durham.  Any  fissure  so  directly  connected  with  a  well 
would  probably  give  indications  of  its  existence  soon  after 
heavy  rains  by  the  effect  upon  the  water  in  the  well 
by  rendering  it  more  or  less  turbid.  In  all  cases  where 
such  turbidity  is  produced,  however  slight,  there  is  cause 
for  anxiety,  and  both  the  well  and  its  surroundings 
should  be  examined  to  ascertain  the  cause.  If  a  heavy 
rainfall  can  wash  into  the  well  visible  particles  it  could 
still  more  easily  carry  with  it  the  minute  organisms  which 
cause  disease,  should  such  unfortunately  happen  to  be 
within  its  sphere  of  influence.  Surrounding  such  wells 
there  should  be  protective  areas,  but  their  form  and  dimen- 
sions could  only  be  defined  after  a  careful  survey  of  the 
district,  more  especially  with  reference  to  the  dip  of  the 
stratum,  and  the  general  direction  of  the  fissures.  The 
locality  where  any  fissures  were  suspected  of  reaching  near 
the  surface  would  require  an  especially  careful  examination. 
If  within  the  well  or  adits  there  were  numbers  of  fissures 
yielding  water  some  useful  information  might  possibly 
be  obtained  by  an  examination,  chemical  or  chemical  and 
bacteriological,  of  the  water  from  those  flowing  most  freely. 
Such  wells  require  careful  watching,  and  frequent  sys- 
tematic analyses  should  be  made  to  ascertain  to  what 
extent,  if  any,  the  quality  of  the  water  is  affected  by  the 
rainfall.  The  greater  the  variation  the  greater  the  risk, 
especially  if  the  variations  rapidly  follow  the  rainfall  and 
are  accompanied  by  an  equally  rapid  variation  in  the  flow. 
If  the  variations  in  character  and  quantity  are  but  slight, 
and  only  occur  some  time  after  the  rainfall,  and  especially 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      355 

if  there  is  never  any  indication  of  turbidity,  then  the  risk 
is  a  minimum  and  may  possibly  be  ignored. 

Deep  wells  drawing  water  from  subterranean  sources 
overlaid  by  thick  beds  of  impermeable  clay  are  generally 
considered  to  yield  the  purest  and  safest  of  waters.  Doubt- 
less where  the  site  has  been  judiciously  selected  and  the 
well  carefully  constructed,  such  is  the  case,  but  deep  wells 
as  well  as  shallow  wells  may  be  defective  in  construction 
and  admit  of  pollution  taking  place.  Wherever  constructed 
the  gathering  ground  feeding  it  must  be  some  distance 
away.  This  outcrop  should  be  examined,  the  more  care- 
fully the  nearer  it  is  to  the  well.  It  is  desirable  to  know 
if  any  possible  sources  of  danger  exist,  even  if  they  cannot 
be  removed,  especially  if  within  one  or  two  miles  of  the 
well.  At  a  further  distance,  possibly  they  may  be  neglected 
as  powerless  for  harm,  the  time  which  would  elapse  between 
the  rainfall  reaching  the  ground  surface  and  the  well 
being  ample  to  secure  a  satisfactory  purification.  The 
chief  source  of  danger  is  from  the  admission  of  possibly 
polluted  subsoil  waters.  It  is  often  difficult  to  effectually 
block  out  the  water  from  superficial  strata,  but  it  can  be 
done,  and  should  be  done.  For  further  security  there 
should  be  a  small  protective  zone  kept  free  from  all  pollu- 
tion. Greater  care  also  should  be  taken  within  the  well 
to>  prevent  dirt,  especially  from  the  shoes,  defiling  the 
staging  and  being  washed  into  the  well.  Samples  of  the 
water  collected  on  a  uniform  plan,  and  at  regular  intervals, 
should  be  submitted  to  analysis  and  careful  records  kept. 
For  this,  however,  to  be  of  real  service  the  water  must  be 
derived  entirely  from  the  deep  source.  If  there  is  a 
variable  admixture  with  subsoil  water,  the  value  of  the 
analytical  record  is  greatly  decreased.  Such  careful  and( 
systematic  analysis  will  detect  any  variations  in  the 
character  of  the  water,  and  possibly  sound  a  note  of  warning 
on  the  approach  of  danger. 

Where  bored  tube  wells  are  used  and  the  tube  forms  the 


356  WATER  SUPPLIES 

suction  pipe  of  the  pump,  danger  of  insuction  of  subsoil 
water,  possibly  contaminated,  certainly  exists  and  should 
be  carefully  guarded  against.  The  action  of  the  pump  is 
to  withdraw  the  atmospheric  pressure  from  within  the 
tube,  and  the  excess  of  pressure  outside  will  force  air  or 
water  through  the  most  minute  defect,  through  apertures 
so  minute  that  under  ordinary  circumstances  neither  would 
have  passed.  When  this  action  has  once  been  set  up, 
the  openings  are  bound  to  increase  in  calibre  and  insuction 
becomes  still  more  easy. 

Whilst  the  deep  wells  constructed  to  supply  large  com- 
munities are  usually  carefully  made,  sufficient  care  does  not 
always  appear  to  be  taken  in  the  construction  of  deep  wells 
when  only  intended  to  supply  a  farm  or  a  few  cottages. 
I  have  known  several  hundreds  of  pounds  spent  in  boring 
and  sinking  such  a  well,  and  then,  to  save  a  few  additional 
pounds,  the  sunk  portion  has  been  so  defective  and  the 
top  so  badly  protected  that  the  water  has  become  polluted. 

Whether  underground  water  be  drawn  from  a  superficial 
or  deep  water-bearing  stratum,  there  is  no  doubt  that  the 
chief  factor  in  protecting  it  from  pollution  is  the  provision 
of  an  area  round  the  well  or  point  of  collection  which  is 
under  the  control  of  the  owners  of  the  well,  and  which  is 
kept  free  from  all  matters  of  an  objectionable  character. 
In  the  past  too  little  care  has  been  taken,  but  it  is  tolerably 
certain  that  in  future  both  Parliament  and  the  Local 
Government  Board  will  insist  upon  efficient  protection, 
and  the  provision  of  ample  protective  areas.  Existing 
sources  of  supply  should  be  examined  and  steps  taken  to 
secure  the  necessary  protection  when  this  is  defective.  If 
such  is  not  possible — and  in  some  instances  this  will 
probably  be  found  to  be  the  case — efforts  should  be  directed 
towards  providing  a  less  dangerous  source  of  supply.  It 
will  be  better  to  voluntarily  abandon  the  works  now  than 
to  wait  until  an  outbreak  of1  typhoid  fever  or  cholera 
arouses  public  indignation  and  compels  their  abandonment. 


PROTECTION  OF  UNDERGROUND  WATER  SUPPLIES      357 

Finally,  all  public  supplies  should  be  periodically 
examined  even  to  the  minutest  detail  and  the  results 
recorded.  These  inspections  should  be  supplemented  by 
chemical  or  chemical  and  bacteriological  analyses  at  more 
frequent  and  regular  intervals.  Were  the  precautions 
above  indicated  universally  adopted,  I  am  convinced  that 
there  would  no  longer  be  any  fear  of  the  specific  pollution 
of  our  underground  water  supplies,  and  that  one  of  the 
most  frequent  causes  of  the  epidemic  prevalence  of  cholera 
and  typhoid  fever  would  cease  to  exist. 


CHAPTER  XIX. 

THE  PROTECTION  OF  SURFACE-WATER  SUPPLIES. 

MUCH  more  attention  has  been  given  in  recent  years  to 
the  protection  from  pollution  of  river,  spring,  and  well 
water,  than  to  the  protection  of  surface-water  sources  of 
supply.  This  is  doubtless  due  to  the  fact  that  all  the 
recent  large  outbreaks  of  typhoid  fever  have  been  due  to 
the  use  of  river  or  spring  water,  and  the  smaller  outbreaks 
to  polluted  shallow  wells. 

Reference  to  the  Local  Government  Board  and  other  re- 
ports on  outbreaks  of  typhoid  fever  shew  that  surface-water 
collected  on  a  large  scale  for  the  supply  of  a  town  or  series 
of  towns  or  villages  has  rarely  been  charged  with  the  spread 
of  that  disease.  This  is  a  subject  of  congratulation  to  those 
towns,  so  numerous  in  the  north  of  England,  deriving  their 
water  from  such  sources.  I  attribute  this  immunity 
entirely  to  one  cause,  the  storage  of  the  water  in  large 
reservoirs.  The  storage  usually  amounts  to  from  100  to  200 
days'  supply.  During  this  storage  the  water  is  fully 
exposed  to  the  air  for  oxidation,  and  to  sunlight  for  insola- 
tion, and  the  long  period  of  rest  secures  more  or  less 
thorough  sedimentation.  I  feel  tolerably  certain  that  the 
typhoid  organisms,  if  introduced  into  such  a  reservoir,  have 
but  a  remote  chance  of  surviving  and  reaching  the  water 
mains  in  a  living  condition.  The  environment  is  dis- 
tinctly unfavourable ;  the  sunshine  quickly  kills  them  as 
they  approach  the  surface,  and  by  sedimentation  they  are 
deposited  with  the  mud  at  the  bottom  of  the  reservoir. 

(358) 


THE  PROTECTION  OF  SURFACE-WATER  SUPPLIES     359 

We  cannot  be  certain,  however,  that  special  conditions 
may  not  arise  permitting  such  organisms  to  reach  the 
mains ;  hence,  apart  from  sentiment,  no  reasonable  effort 
should  be  spared  to  prevent  the  pollution  of  the  water  by 
any  matter  which  could  possibly  be  infected.  To  secure 
at  all  times  a  thoroughly  wholesome,  bright,  and  palatable 
water  should  be  the  aim  of  every  authority  having  control 
of  any  public  water  supply. 

Where  full  control  of  the  collecting  area  is  secured  and 
the  whole  converted  into  prairie  land  without  houses  or 
farms,  mines  or  other  works  upon  it,  and  with  but  few 
public  thoroughfares,  and  the  storage  reservoir  is  of  very 
large  size,  filtration,  may  possibly  be  dispensed  with,  but 
although  it  ceases  to  be  a  very  important  factor,  I  should 
always  regard  it  as  highly  desirable. 

To  obtain  full  control  of  a  gathering  ground  is,  however, 
a  very  difficult  and  often  impossible  procedure.  The 
subject  was  thoroughly  discussed  recently  before  a  Parlia- 
mentary Committee  when  a  Bill  was  being  considered  in 
which  a  water  authority  sought  to  obtain  this  complete 
control.  Partial  control  had  already  been  obtained  and 
many  houses  demolished.  Certain  farms  had  been  acquired 
and  laid  down  entirely  to  grass.  There  were  many  foot- 
paths, certain  highways,  stone  quarries,  etc.,  and  the 
evidence  showed  that  so  many  interests  were  involved, 
public  and  private,  that  absolute  control  was  impossible. 
People  walking  along  these  footpaths  and  mads  in  secluded 
districts  cannot  be  prevented  from  obeying  the  calls  of 
Nature.  Accommodation  may  be  provided  at  quarries, 
but  no  one  can  compel  the  men  to  use  them  and  them  only. 
Hence  when  all  has  been  done  there  are  risks  which  must 
be  run  and  against  which  some  other  mode  of  protection 
must  be  devised.  In  this  country,  which  is  becoming  more 
and  more  thickly  populated,  and  where  even  the  most 
remote  districts  have  charms  for  tourists,  I  doubt  very 
much  whether  any  upland  surface  can  be  kept  absolutely 
free  from  pollution. 


360  WATER  SUPPLIES 

Ample  storage  may  possibly  be  in  many  cases  a  sufficient 
safeguard  but,  as  we  shall  see  shortly,  there  are  other 
reasons  for  preferring  nitration  also. 

There  are  many  gathering  grounds,  however,  where  such 
efficient  protection  is  impossible,  and  where  a  certain, 
amount  of  pollution  by  manurial  or  sewage  matter  is 
unavoidable.  These  are  districts  in  which  more  or  less  of 
the  land  is  under  cultivation.  The  land  may  be  so  valuable 
that  purchase  is  out  of  the  question,  or  there  may  be  other 
insurmountable  difficulties  with  reference  to  its  acquisition. 

Even  in  these  cases  very  often  great  improvements  may 
be  effected  by  efficient  supervision  of  the  sanitary  arrange- 
ments, scavenging,  etc.,  by  constructing  drains  and  sewers 
to  convey  the  polluting  matter  beyond  the  boundary  of  the 
watershed,  by  arranging  that  no  manure  containing  human 
excrement  shall  be  used.  Where  such  arrangements  cannot 
be  made  the  question  must  arise  as  to  whether  the  water- 
shed should  not  be  abandoned  or  whether  the  storage  with 
nitration  can  be  depended  upon  for  preventing  any  infective 
matter  reaching  the  mains.  Every  case  of  this  kind  must 
be  discussed  on  its  merits,  and  after  a  thorough  and 
systematic  examination  of  the  watershed.  I  have  seen 
reservoirs  inefficiently  protected  and  with  footpaths  along 
the  banks.  On  these  footpaths  I  have  seen  human  excre- 
ment, and  in  the  water  I  have  seen  drowned  animals.  It 
is  obvious,  therefore,  that  so  far  as  is  possible  both  animals 
and  human  beings  should  be  prevented  from  gaining  access 
to  the  reservoirs.  Sometimes  the  water  from  such  an 
unsatisfactory  collecting  area  can  be  utilised  as  compensa- 
tion water  for  manufacturing  purposes. 

Where  surface-water  supplies  are  used  a  large  storage 
is  always  necessary,  in  order  to  impound  water  during 
the  wet  seasons  for  use  during  the  dry.  This  alone  assures 
storage  sufficient  for  hygienic  purposes,  for  bleaching,  more 
or  less  completely,  peaty  waters,  for  allowing  sedimentation, 
and  time  for  the  destruction  of  the  typhoid  microbe.  The 


THE  PROTECTION  OF  SURFACE-WATER  SUPPLIES     361 

greater  the  storage,  the  better  for  all  these  purposes.  As 
previously  stated,  such  storage  is  probably  sufficient,  save 
under  very  exceptional  circumstances,  to  insure  safety. 
If  the  water  gets  very  low,  however,  in  the  early  autumn, 
and  very  heavy  rains  come  on  suddenly,  it  is  quite  possible 
for  impure  water  to  reach  the  mains.  After  a  long  dry 
season,  polluting  matter,  if  any,  would  accumulate  on  the 
watershed  and  be  washed  down  with  the  first  storm.  The 
water  then  would  be  unusually  polluted,  and  it  would 
have  unusual  facilities  for  rapidly  traversing  the  storage 
reservoirs  and  reaching  the  consumers.  Efficient  filtration 
would  now  be  the  last  and  only  line  of  defence. 

Filtration,  efficiently  conducted,  would  at  such  times 
prevent  99  per  cent,  of  the  organisms  from  entering  the 
mains,  and  experience  teaches  that  the  risk  of  using  such 
a  water,  properly  filtered,  is  very  small  indeed.  But  apart 
from  protection  from  infection  filtration  is  almost  indis- 
pensable, if  we  wish  at  all  times  to  supply  a  bright  and 
palatable  water.  We  cannot  prevent  low  forms  of  vegetable 
and  animal  life  being  carried  into  the  reservoirs,  nor  can 
we  prevent  their  multiplication  therein.  If  the  water 
is  not  filtered,  these  are  delivered  with  the  water  to  the 
consumers,  and  impart  to  the  water  an  unsightly  appear- 
ance, and  sometimes  a  very  disagreeable  odour.  Even 
when  not  visible  at  the  time  of  delivery,  they  may  so 
rapidly  multiply  afterwards,  that  vessels  in  which  the  water 
has  stood  for  a  night  or  two  become  coatecl  with  a  more  or 
less  slimy  deposit,  or  with  a  distinct  green  growth.  This 
condition  is  one  which  frequently  causes  loud  complaints, 
and  such  a  water  cannot  be  regarded  as  sufficiently  satis- 
factory for  a-  public  supply. 

To  sum  up,  I  strongly  advocate  three  distinct  lines  of 
defence : 

1.  The    utmost    possible    control    of    the    watershed    or 
collecting  area. 

2.  Very  ample  storage. 

3.  Sand  filtration. 


362  WATER  SUPPLIES 

Where  the  water  is  acid,  or  has  a  plumbosolvent  action, 
the  filtration  should  be  through  a  mixture  of  sand  and 
limestone,  and  the  softer  the  limestone  the  better,  the 
object  being  to  neutralise  the  acid  and  cause  the  water  to 
dissolve  a  small  quantity  of  carbonate  of  lime,  as  by  this 
means  the  plumbo-solvent  action  is  more  or  less  completely 
destroyed. 

The  Local  Government  Board  has  recently  issued  a 
circular  bearing  upon  the  protection  of  water  supplies,  and 
suggests  that  every  sanitary  authority  should  obtain  accu- 
rate information  in  such  matters  as  the  following :  — 

1.  Where    water    is    derived    from    gathering-grounds    or 
from  springs.     Whether  drainage  from  human  habitations, 
farm-yards,  and  the  like  finds  its  way  directly  or  indirectly 
into  the  reservoir  or  to  any  part  of  the  water  service,  and 
whether  risk  of  access  to  the  water  of  human  excreta  and 
similar  refuse  is  likely  to  arise. 

2.  Where   water   is    derived    from    deep    wells.     Whether 
surface  or  other  water  liable  to  be  contaminated  by  drains, 
sewers,  cesspools,  and  the  like  reaches,  or  is  liable  to  reach, 
the  wells.     The  existence  and  direction  of  fissures  in  the 
strata  deserve  especial  consideration  in  this  respect. 

3.  Where  water  is  derived  from  shallow  wells.     Whether 
the    wells    are    so    circumstanced    that    they    run    risk    of 
contamination  by  reason   of   drains,   privies,    cesspools,    or 
middens,   or  by  the  deposit   of  manure — whether  derived 
from  human  excreta  or  n,ot — in  or  on  the  ground  in  the 
neighbourhood  of  the  wells. 

The  district  councils  are  reminded  that  they  are  respon- 
sible for  the  wholesomeness  of  water  which  they  themselves 
supply,  and  that  they  should  by  careful  inquiry  make 
themselves  acquainted  with  the  sources,  nature,  and  quality 
of  the  various  supplies  in  all  parts  of  their  districts. 

This  circular  letter  would  have  been  more  complete  had 
it  also  directed  attention  to  section  7  of  the  Public  Health 
(Water)  Act,  which  renders  it  obligatory  on  the  part  of 


THE  PROTECTION  OF  SURFACE-WATER  SUPPLIES    363 

every  rural  sanitary  authority  from  time  to  time  to  take 
such  steps  as  may  be  necessary  to  ascertain  the  condition 
of  the  water  supply  within  their  district,  and  authorises 
the  payment  of  all  reasonable  costs  and  expenses  incurred 
by  them  for  this  purpose. 


CHAPTER  XX. 

WELLS  AND  THEIR  CONSTRUCTION. 

THE  practice  of  obtaining  water  by  means  of  wells  sunk  in 
the  subsoil  is  one  which  dates  from  the  remotest  antiquity, 
and  at  the  present  time  a  very  large  proportion  of  the 
population  of  the  globe  derives  its  supply  of  water  from 
such  sources.  In  Great  Britain  it  is  estimated  that  over 
one-third  of  the  population  is  so  supplied.  Whilst  in 
every  other  department  of  engineering  improvements  have 
advanced  with  rapid  strides,  especially  in  recent  years, 
shallow  wells  continue  to  be  constructed  in  almost  precisely 
the  same  way  as  they  were  thousands  of  years  ago.  The 
well-sinker  is  the  most  conservative  of  men,  and  in  most 
districts  it  is  impossible  to  get  a  well  constructed  so  as  to 
protect  the  water  from  pollution.  To  the  country  well- 
sinker  a  well  is  merely  a  reservoir  to  contain  water,  and 
whether  this  water  enters  from  the  bottom,  side,  or  top 
he  considers  a  point  unworthy  of  consideration,  and  in  fact 
he  makes  the  well  in  such  a  manner  that  water  can  freely 
enter  it  at  all  points.  The  result  is,  that  as  wells  are,  for 
convenience,  almost  invariably  sunk  in  close  proximity  to 
inhabited  houses,  impurities  from  the  soil,  from  defective 
drains,  cesspits,  and  cesspools  readily  gain  access  and  foul 
the  purer  water  which  enters  at  a  greater  depth.  It  is 
not  surprising  therefore  that  the  great  majority  of  such 
wells  yield  water  which  is  always  impure,  and  liable  at  any 
moment  to  become  specifically  contaminated  and  produce 
an  outbreak  of  disease.  The  time-honoured  custom  of 

(364) 


WELLS  AND  THEIR  CONSTRUCTION  365 

lining  the  well  with  bricks,  set  dry,  and  resting  upon  a 
wooden  curb,  still  almost  universally  prevails.  The  brick- 
work may  be  carried  right  up  to  the  surface  and  the  well 
left  open,  or  it  may  be  covered  with  a  lid,  in  which  case'it 
is  frequently  so  left  that  the  water  spilt  upon  withdrawing 
the  bucket  runs  back  into  the  well,  carrying  with  it  filth 
from  the  surface  of  the  ground  around,  and  during  a  heavy 
rainfall  the  surface  water  runs  directly  into  the  well. 
Where  the  well  is  covered  up,  the  cover  is  generally  near 
the  surface,  and  may  consist  of  old  railway  sleepers  or  logs 
of  wood  admitting  water  freely.  Even  if  no  sewage  matters 
enter  such  wells,  the  wooden  curb  and  the  rotting  wooden 
covering  yield  putrid  organic  matter  to  the  water.  Draw 
wells  and  dipping  wells  are  also  liable  to  be  contaminated 
by  the  dirty  vessels  let  down  into  them,  by  frogs,  rats,  and 
other  animals  getting  in,  and  by  dead  leaves  and  other 
matters  blown  by  the  wind.  The  animal  and  the  vegetable 
substances  by  their  death  and  decay  foul  the  water.  In 
wells  otherwise  carefully  constructed  it  is  often  found  that 
impure  water  can  gain  access  along  the  track  of  the  pipe 
leading  from  the  pump  to  the  well. 

In  a  properly-constructed  well  no  water  should  be  able 
to  enter  except  from  near  the  bottom,  so  that  before 
reaching  the  well  it  must  have  passed  through  a  consider- 
able thickness  of  subsoil,  becoming  in  its  course  thoroughly 
filtered  and  purified.  Various  methods  of  accomplishing 
this  difficult  task  have  been  suggested;  but  as  there  are 
other  ways  of  obtaining  subsoil  water,  which  are  more 
simple  and  far  more  satisfactory,  we  may  reasonably  hope 
that  ere  long  the  ordinary  form  of  shallow  well  will  be 
abandoned.  Before  describing  these  other  methods,  how- 
ever, the  best  ways  of  constructing  wells  may  be  briefly 
referred  to.  Where  the  excavation  is  through  solid  rock, 
such  as  chalk,  limestone,  or  sandstone,  the  steindng,  or 
lining  with  a  cylinder  of  brickwork  or  of  iron  or  other 
material  will  only  be  necessary  to  keep  out  the  water  from 


366  WATER  SUPPLIES 

the  more  pervious  surface  soil.  If  bricks  be  employed 
they  must  be  well  bedded  on  the  rock  with  cement,  and  the 
whole  of  the  brickwork  lined  inside  with  hydraulic  cement, 
arid  the  lining  continued  some  distance  below  the  last  layer 
of  bricks  on  to  the  exposed  surface  of  the  rock,  so  as  to 
render  the  junction  as  impervious  as  possible.  The  brick- 
work should  also  be  well  puddled  behind.  Where  the  rock 
is  not  freely  porous  water  may  accumulate  in  the  loose 
subsoil,  and  unless  the  greatest  care  be  taken  it  will  enter 
the  well.  In  the  most  modern  wells  cast-iron  or  wrought- 
iron  cylinders  are  employed  for  lining  the  upper  portion 
in  order  to  keep  out  the  surface  water  and  land  springs. 
Similar  cylinders  are  also  employed  to>  keep  out  water  from 
fissures  which  may  be  met  with  in  excavating  the  well. 
Where  the  subsoil  is  clay  and  impervious  these  precautions 
are  of  course  not  necessary.  In  ordinary  wells,  sunk 
throughout  in  a  porous  subsoil,  the  lining  should  consist  of 
two  separate  rings  of  4J-inch  brickwork  laid  in  cement  and 
lined  with  cement  to  a  depth  of  10  or  12  feet  from  the 
surface.  As  this  class  of  work  is  somewhat  expensive,  and 
the  cement  is  liable  to  fracture,  either  by  the  inward 
pressure  of  the  sides  of  the  well  or  other  causes,  earthenware 
tubes  are  now  being  made  by  the  Leeds  Fireclay  Company 
for  lining  purposes.  The  ground  having  been  excavated  as 
deep  as  can  be  done  with  safety,  a  tube  is  dropped  in  and 
some  well-puddled  clay  laid  on  the  bevelled  edge  and 
another  tube  lowered.  If  properly  driven  the  tubes  fit  well 
together.  The  tubes  are  lowered  by  aid  of  ropes,  blocks, 
and  cross-bars.  Having  got  in  the  tubes,  a  man  can  easily 
work  inside  and  undermine  the  edge,  when  the  weight  will 
cause  them  to  descend.  Of  course  the  joints  are  afterwards 
"  pointed  "  inside  with  cement  so  as  to  make  them  more 
secure,  and  it  is  advisable  to  try  all  the  tubes,  fitting  and 
marking  them  before  using.  Or  the  well  may  be  con- 
structed in  the  ordinary  manner,  dry  steined  with  4|-inch 
brickwork  if  necessary,  and  the  tubes  then  lowered  and 


WELLS  AND  THEIR  CONSTRUCTION  367 

fitted  and  puddled  behind  with  clay.  Dry-steined  wells 
at  present  in  existence  might  with  advantage  be  converted 
into  tube  wells  in  this  manner.  The  well  itself  having  been 
so  constructed  as  to  prevent  the  possibility  of  water 
entering  anywhere  except  at  the  bottom,  it  remains  still 
to  cover  it  in  and  protect  the  top.  The  best  plan  is  to 
project  the  dome  of  the  well  6  or  12  inches  above  the 
surface  of  the  ground  and  securely  cover  with  a  properly- 
fitting  iron  cover.  By  this  means  easy  access  is  at  any  time 
gained  for  cleansing  or  examining  purposes.  The  pump 
should  be  fixed  some  little  distance  from  the  well,  and  the 
drain  carrying  away  the  waste  water  should  not  go  near  it. 
Every  care  should  be  taken  to  render  water-tight  the 
aperture  through  which  the  pump  pipe  passes,  and  it 
should  be  bedded  in  clay  or  cement  so  as  to  prevent  the 
water  or  rats  forming  a  track  alongside  the  pipe  through 
which  impurities  can  gain  access  to  the  water  in  the  well. 
Probably  the  best  plan  is  to  solder  a  baffle  plate  to  the 
suction  pipe  and  imbed  this  plate  in  the  side  of  the  well. 
If  the  sides  of  the  well  be  covered  up  to  a  sufficient  height 
above  the  ground,  the  pump  may  be  fixed  inside,  the 
handle  and  spout  only  projecting  outside.  A  hooded 
aperture  at  the  top  can  be  left  for  ventilation. 

Quite  recently  I  have  seen  wells  the  upper  portions  of 
which  were  constructed  from  the  halves  of  old  steam 
boilers,  the  domed  end  of  the  boiler  forming  the  top  of  the 
well  and  a  hole  being  drilled  through  the  side  for  the 
pump  pipe  to  enter.  To  prevent  the  action  of  a  soft  water 
upon  the  iron,  it  is  desirable  that  the  whole  of  the  interior 
should  be  lined  with  cement. 

Koch,  in  his  work  on  Water  Filtration  and  Cholera,  whilst 
condemning  strongly  the  ordinary  shallow  well,  recognises 
the  fact  that  it  is  impossible  to  arrange  that  those  already 
existing  should  be  abandoned.  He  therefore  recommends 
that  the  construction  should  be  so  altered  as  to  remove  all 
danger  of  contamination  fr.Qm  above.,  *'  To  achieve  this. 


368  WATP:R  SUPPLIES 

one  should  proceed  by  filling  up  the  well  to  the  highest 
water  point  with  gravel,  and  over  the  gravel  with  sand  up  to 
the  very  top."  Of  course  an  iron  pipe  should  traverse  the 
sand  and  gravel  and  be  connected  with  the  pump.  A  well 
so  constructed  "  gives  the  same  protection  against  the 
infection  of  water  as  is  given  by  the  sand  nitration  of  the 
great  waterworks.  In  fact  it  really  gives  a  greater  pro- 
tection, since  it  is  not  exposed  to  the  many  disturbances 
in  the  process  of  nitration  already  referred  to,  and  is  also 
not  affected  by  frost."  So  much  attention  is  now  being 
given  to  perfecting  as  much  as  possible  the  water  supply 
of  the  great  waterworks,  that  it  is  important  not  to>  lose 
sight  of  the  domestic  water  supply  by  pumps  and  wells. 
By  improving  the  wells  in  the  manner  explained  above, 
."  the  spread  of  cholera,*  in  so  far  as  it  is  due  to  water,  can 
be  restricted  to  a  great  extent.  It  is  just  in  this  respect 
that  a  great  deal  can  yet  be  done."  This  suggestion  of 
Koch's  is  one  worthy  of  consideration,  since  the  change 
can  be  effected  at  a  minimum  of  expense,  and  the  result 
leaves  little  to  be  desired.  It  is  important,  however,  to 
remember  that  the  superficial  layer  of  sand  should  be  at 
least  6  feet  in  thickness.  Where  the  subsoil  water  is 
reached  at  a  less  depth  than  6  feet,  probably  this  method 
will  not  afford  complete  protection  in  many  cases.  Dr. 
R.  Kempster,  in  his  researches  on  "  The  influence  of 
different  kinds  of  soil  on  the  cholera  and  typhoid  organ- 
isms," arrived  at  the  following  conclusions  :  "  White  crystal 
sand,  yellow  sand,  and  garden  earth  have  no  marked 
favourable  or  injurious  action  on  the  life  of  the  organisms. 
The  length  of  life  of  the  organisms  in  the  soil  depends 
chiefly  on  the  amount  of  moisture  present.  Peat,  on  the 
contrary,  is  very  de'adly  to  both  the  comma  and  typhoid 
bacillus.  The  soil  acts  as  a  good  filter,  holding  back  most 
of  the  organisms,  but  it  is  possible  for  these  organisms  to. 

*  And  of  typhoid  fever  §nd  other  diseases  disseminated  by  water. 


WELLS  AND  THEIR  CONSTRUCTION  36$ 

be  carried  through  2J  feet  of  porous  soil  by  a  current  of 
water."  Where  the  ground  water-level,  therefore,  is  within 
5  or  less  feet  from  the  surface,  the  side  of  the  well  should 
be  rendered  impervious  to  a  depth  of  10  or  12  feet,  or, 
better  still,  the  water  should  be  obtained  by  aid  of  an 
Abyssinian  tube  well,  next  to  be  described,  driven  to  at 
least  this  depth. 

In  a  great  many  instances  subsoil  water  can  be  obtained 
without  the  trouble  and  expense  of  well-digging,  merely 
by  driving  iron  tubes  through  the  ground  until  the  subsoil 
water  is  reached,  and  fixing  a  pump  to  the  upper  end  of  the 
tube.  Such  tube  wells  were  first  used  systematically  during 
the  Abyssinian  campaign,  hence  they  are  now  popularly 
known  as  "  Abyssinian  "  tube  wells.  They  are  most  suitable 
for  gravel,  coarse  sand,  chalk,  and  similar  porous  water- 
bearing strata,  and  for  depths  not  exceeding  40  to  50  feet, 
though  under  exceptional  circumstances  tubes  have  been 
driven  successfully  to  a  depth  of  150  feet.  Naturally  they 
cannot  be  driven  through  hard  rock,  neither  are  they 
suitable  for  obtaining  water  from  marl,  fine  sand,  or  clay 
formations,  since  the  apertures  in  the  perforated  terminal 
tube  are  liable  to  become  blocked  by  the  fine  particles  of 
which  such  strata  are  composed.  A  pointed  perforated 
tube  is  driven  into  the  ground  by  aid  of  a  "  monkey." 
(The  tubes  vary  from  1J  to  4  inches  in  diameter,  according 
to  the  amount  of  water  which  it  is  desired  to  raise.)  When 
this  tube  has  been  well  driven,  a  second  tube  is  screwed  on 
to  the  first  and  the  driving  resumed.  By  lowering  a 
plummet  down  the  tubes  from  time  to  time,  it  can  be 
ascertained  whether  water  has  been  reached  or  whether 
sand  or  earth  is  filling  up  the  end  of  the  perforated  tube. 
When  water  is  reached  a  pump  can  be  attached  and  a 
sample  drawn  for  examination,  and  the  quantity  available 
ascertained.  If  either  the  quantity  or  quality  be  unsatis- 
factory, the  tubes  can  be  driven  deeper,  or  they  can  be 
withdrawn  and  redriven  in  another  spot.  A  well  of  this 

24 


WATER  SUPPLIES 

character  is  shown  in  Fig.  20. 
Very  often,  where  the  supply  from 
an  ordinary  sunk  well  is  limited, 
it  can  be  increased  by  driving 
one  or  more  of  the  "  Abyssinian  " 
tubes  from  the  bottom  of  the  well. 
Special  pointed  and  perforated 
tubes  are  employed  where  the 
soil  is  ferruginous  or  likely  to 
corrode  the  metal  of  the  ordinary 
tube.  Tubes  designed  to  prevent 
plugging  with  sand  are  useful 
under  certain  circumstances,  as 
when  the  water-bearing  strata 
contains  together  with  the  sand  a 
fair  proportion  of  grit.  In  fine 
sandy  soils,  however,  it  is  better 
to  withdraw  the  tubes,  ram  down 
a  lot  of  fine  gravel,  and  redrive. 

In  the  "  Abyssinian  "  tube  well 
the  water  is  drawn  directly  from 
the  water-bearing  stratum,  there 
being  no  reservoir.  At  first  the 
water  invariably  contains  fine 
sand  or  chalk,  according  to  the 
nature  of  the  subsoil,  but  after  a 
time  a  clear  water  is  yielded.  This 
is  probably  due  to*  the  removal 
of  all  th,e  fine  particles  and 
debris  from  around  the  terminal 
tube  and  the  formation  of  a 
natural  cavity  in  which  the  water 
accumulates.  In  suitable  locali- 
ties these  tube  wells  answer  ad- 
mirably, and  not  only  are  cheaper 
to  sink,  but  yield  a  safer  supply 
of  water  than  a  sunk  well.  One 


FIG.  20.— Abyssinian  Tube  Well. 


WELLS  AND  THEIR  CONSTRUCTION 


371 


man,  usually,  can  drive  the  smallest^sized  tubes,  but  three 
or  four  men  are  required  for  the  largest  tubes.  In  very 
light  soil  a  30-feet  well  may  be  driven  in  less  than  one 
day;  in  a  firmer  soil  three  days  may  be  required.  What- 
ever the  depth  of  the  tube  well  an  ordinary  pump  will 
raise  the  water,  provided  the  water  level  in  the  tube  is 
within  25  feet  of  the  surface.  If  the  water  stand  at  a 
lower  level,  a  deep  well  pump  must  be  provided. 

The  capacity  of  these  tube  wells  varies  with  the  depth, 
yield  of  spring,  and  power  of  pump  applied. 

The  following  are  the  estimates  of  two  of  the  best-known 
firms  of  well-sinkers :  — 


Size  of  Well. 

Yield  in  Gallons  per  Hour. 

Authority. 

IJin. 

150  to     600 

Le  Grand  and  Sutcliff 

2  . 

300  to  1,200 

3 

600  to  2,400 

4 

1,200  to  4,400 

»                  » 

li 

150  to     900 

C.  Isler  and  Co. 

2 

300  to  1,500 

»            » 

3 

450  to  3,000 

»            >» 

Messrs.  Le  Grand  and  Sutcliff  have  kindly  furnished  me 
with  the  following  table  (see  page  372),  giving  the  depth  of 
well,  size  of  tube,  yield  of  water  per  hour  of  a  series  of 
typical  wells  driven  by  them,  which  bear  out  the  above 
statements. 

Not  only  are  these  tube  wells  preferable  to  sunk  wells 
on  account  of  the  greater  freedom  from  risk  of  contamina- 
tion, but  they  are  much  less  expensive.  The  probable 
cost  of  a  well  can  easily  be  calculated  from  the  following 
estimates  (see  page  373). 


WATER  SUPPLIES 


bear 
tum 


r- 
ra 


r  r^r^ 

11 

^3  nS       t3 

a          a      ft 


"a  . 


WELLS  AND  THEIR  CONSTRUCTION 


373 


Twelve-Feet  Tube 
with  Hire  of  Plant 
and  Man  to  Superin- 
tend Driving. 

Add  for  each 
additional 
Foot. 

Pump,  Column,  and 
Foundation. 

1^-inch  tube 

£240 

3s. 

£2  10  0  to  £3  10  0 

2 

3  10    0 

4s.  6d. 

3 

7  10     0 

10s. 

£3  10  0  to  £4  10  0 

4 

9  15     0 

13s. 

"         . 

To  the  above  must  be  added  the  man's  time  in  travelling, 
railway  fares,  carriage  of  materials,  etc.  A  well  recently 
driven  in  one  of  my  districts  to  a  depth  of  17  feet,  a  2-inch 
tube  being  used,  cost  £8  12s.  4d.,  the  items  being  as  under. 


17-feet  2-inch  tube  well  . 

4-inch  column,  pump,  and  foundation 

Hire  of  man  and  plant     . 

Man's  time  travelling 

Railway  fare  and  carriage 


Total 


£2  14  6 
380 
1  10  0 
076 
0  12  4 


£8  12     4 


The  wages  of  the  agricultural  labourer  who  assisted  in 
driving  the  tube  is  not  included,  but  would  not  exceed  5s. 

These  prices  may  be  compared  with  the  following 
schedule  of  prices  taken  from  Sir  R.  Rawlinson's 
Suggestions  as  to  the  Preparations  of  Plans  for  Drainage 
and  Water  Supply  (Local  Government  Board,  1878). 

Schedule  of  prices  for  sinking  wells  in  Clay,  lined  with 
9-inch  brickwork  in  Portland  Cement.  Wooden  curves, 
cylinders,  and  pumping  extra. 


4  feet  diameter  to  depth  of  200  feet,    50s.  per  foot  run 

5  „  „          200    „       65s. 

6  „  „          200    „       85s. 

7  200    ,       105s. 


374 


WATER  SUPPLIES 


Rough  estimate  of  well-sinking,  through  Clay,  Chalk,  and 
Gravel,  entirely  exclusive  of  brickwork  or  fittings. 


Diameter  of  Well. 

Depth. 

Price  per  Foot  of  Depth. 

Total  Cost. 

4  feet 
5     „ 

50  feet 
50    „ 

3s. 
4s.  6d. 

£7  10     0 
11     5     0 

Where  hard  rock  has  to  be  pierced  or  where  the  water- 
bearing stratum  lies  at  a  considerable  depth  below  the 
ground  surface,  the  well  must  either  be  excavated  or  bored. 
The  cost  of  sinking  as  compared  with  boring  is  so-  excessive 
that  nearly  all  deep  wells  are  now  bored.  Not  only  is  the 
cost  much  less,  but  as  the  bore-hole  is  lined  with  metal  tubes 
(which  should  be  of  wrought  iron,  lap-welded  and  steel- 
socketed),  surface  springs  are  excluded,  and  the  possibility 
of  contamination  reduced  to  a  minimum.  Various  methods 
are  employed  and  many  different  kinds  of  tools,  according 
to  the  nature  of  the  strata  to  be  penetrated,  and  the  depth 
and  the  manner  of  the  borings,  which  vary  from  3  to  18 
inches  in  diameter;  but  in  soft  rock,  like  chalk,  this 
diameter  may  be  greatly  exceeded.  In  the  majority  of 
cases  the  borings  are  made  from  the  bottom  of  a  dug  well, 
the  object  usually  being  twofold  :  (a)  to  form  a  storage 
reservoir  for  the  water ;  and  (6)  to  provide  a  receptacle  for 
the  pumps.  It  is,  however,  found  that  in  many  cases  the 
dug  well  can,  with  advantage,  be  dispensed  with.  It  is 
only  really  necessary  where  the  spring  is  weak  and  the 
demand  for  water  intermittent.  Such  dug  wells,  unless 
very  carefully  constructed,  also  increase  greatly  the 
liability  to  contamination  by  surface  water.  During  the 
process  of  boring  a  number  of  springs  may  be  tapped,  and 
the  quality  of  the  water  yielded  by  each  can  be  ascertained 
by  analysis.  If  it  be  ultimately  found  that  one  of  the 
upper  springs  yields  the  most  suitable  water,  the  tubes 
can  be  withdrawn  and  the  hole  plugged  at  such  a  depth 


srr 

x-' 

AND  THEIR  CONSTRUCTION  375 

that  only  water  from  that  particular  spring  is  supplied. 
In  the  older  wells  the  tubes  lining  the  bore  are  usually 
not  continuous^  and  water  from  divers  sources  has  free 
access  to  the  wells.  In  the  more  modern  borings  larger 
tubes  are  used  for  convenience  in  boring,  and  a  smaller 
tube  with  tight  joints  is  then  inserted,  reaching  from  the 
surface  to  the  bottom  of  the  well.  The  outer  tubes  may 
be  afterwards  withdrawn  or  the  space  between  the  two 
filled  in  with  cement.  With  such  a  continuous  tube  the 
pump  can  be  so  attached  that  the  water  is  drawn  directly 
from  the  bottom  of  the  well.  The  conditions  which 
influence  the  yield  of  water  from  bored  wells  are  so  lucidly 
expressed  by  Mr.  R.  Sutcliff,  in  a  paper  read  before  the 
Brewers'  Congress  in  1886,  that  no  apology  is  required 
for  reproducing  them  here.  "  The  continuous  tube,"  says 
Mr.  Sutcliff,  "  has  an  important  bearing  on  the  yield  from 
the  spring;  the  weight  of  the  atmosphere  being  removed 
by  the  pump  from  the  surface  of  the  water  in  the  tube 
well.  This,  as  regards  the  velocity  of  the  flow  of  the 
spring,  is  equivalent  to  drawing  the  water  from  some  34 
or  35  feet  lower  than  is  possible  when  the  weight  of 
atmosphere  presses  on  the  surface  of  the  water.  The 
increase  in  supply  under  these  conditions  is  equal  to  about 
40  per  cent.,  which  acts  as  an  important  compensation  for 
absence  of  storage.  It  may  be  interesting  to  give  an 
example  of  this.  A  dug  well,  25  feet  deep  and  of  5  feet 
diameter,  will  hold  3,050  gallons  of  water.  Suppose  that 
such  a  well  is  supplied  by  a  spring  which,  when  the  head 
of  25  feet  is  removed  from  it,  will  flow  at  the  rate  of  950 
gallons  per  hour.  As  the  maximum  flow  is  only  obtainable 
after  the  storage  is  completely  exhausted,  the  average 
yield  must  be  taken  until  that  exhaustion  occurs.  Let 
the  pumps  be  started  to  draw  1,500  gallons  per  hour,  the 
quantity  obtained  by  the  storage  will  be  exhausted  in  two 
hours.  But  as  in  that  time  the  spring  would  have  been 
yielding  an  average  flow  of,  say,  700  gallons  per  hour,  the 


376  WATER  SUPPLIES 

well  would  not  be  emptied  until  the  pumps  had  been  going 
about  four  hours.  When  that  time  had  expired,  the 
spring  would  be  yielding  its  maximum  of  950  gallons  per 
hour,  and  the  speed  of  the  pumps  would  have  to  be 
slackened  proportionately.  Under  these  conditions,  a  total 
of  11,500  gallons  would  be  drawn  from  the  well  in  ten 
hours. 

"  Let  a  tube  well  be  placed  under  exactly  similar  circum- 
stances as  regards  supply  and  water  level.  The  pumps 
drawing  from  a  tube  well  could  get  950  gallons  per  hour 
plus  40  per  cent. ;  that  is  to  say,  1,330  gallons  per  hour. 
Therefore,  the  tube  well  would  in  10  hours  yield  13,300 
gallons — a  gain,  in  that  time,  in  spite  of  absence  of 
storage,  of  1,800  gallons;  and  the  pumping  from  the  tube 
well  could  be  continued  uniformly  at  the  same  speed  for 
an  indefinite  period,  so  long  as  the  spring  maintained  its 
flow. 

"  When  the  normal  level  of  the  spring  is  not  sufficiently 
near  the  surface,  or  the  flow  is  not  rapid  enough  to  enable 
an  ordinary  lift  pump  to  draw  the  water,  the  tube'  well 
must  be  made  of  such  size  as  will  enable  a  deep  well  pump 
to  be  placed  in  it,  as  far  below  the  surface  of  the  water 
as  may  be  necessary  to  obtain  the  required  supply.  A  deep 
well  pump  can  be  placed  150  or  even  200  feet  below  the 
surface;  but  when  it  becomes  necessary  to  place  it  at  that 
depth  below  the  water  level,  the  supply  required  is  one 
that  is  very  great  compared  with  the  spring  that  yields  it. 
Because,  although  all  springs  increase  until  the  base  of 
them  is  reached,  that  augmentation  is  a  constantly  decreas- 
ing one.  The  reason  for  this  decrease  is  obvious.  The  water 
flows  through  channels  of  fixed  area.  When  the  head  of 
water  is  removed,  the  pressure  is  increased  proportionately 
with  the  depth  that  the  water  is  lowered ;  but  the  friction 
of  passing  through  the  channels  also  increases.  So  that  to 
double  the  supply  that  flows  at  150  feet  below  the  head  of 
the  spring,  it  would  be  necessary  to  place  the  pump  600 


WELLS  AND  THEIR  CONSTRUCTION  377 

feet  under  water.  These  facts  are  of  the  highest  import- 
ance in  deciding  whether  a  given  spring  can  meet  the 
requirement  of  the  consumer.  Let  it  be  supposed  that  two 
borings  are  made,  and  that  springs  are  tapped  by  these 
borings,  which  both  overflow  the  surface  of  the  ground  at 
the  rate  of  10  gallons  per  minute.  To  the  casual  observer 
both  of  these  springs  might  be  considered  as  equal.  But 
one  might  be  ten  times  stronger  than  the  other.  Let  us 
call  these  springs  A  and  B.  The  spring  A,  when  we  lower 
by  pumping,  gives  no  appreciable  increase ;  whereas  the 
spring  B,  when  we  lower  it  only  3  feet,  yields  double  the 
quantity  of  water.  Why  is  this?  If  it  were  possible  to 
carry  the  pipes  up  from  which  spring  A  flows,  we  should  find 
that  the  water  would  rise  100  feet  before  it  came  to  rest; 
whereas  with  spring  B,  if  we  only  piped  it  1  foot  higher, 
it  would  cease  to  flow.  This  would  prove  that  spring  A 
is  a  high-pressure  one,  the  source  of  which  is  99  feet  above 
the  ground  level;  but  spring  B  has  its  source  only  about 
1  foot  above  the  ground  level.  The  channels  of  communica- 
tion in  spring  A  are  small,  and  the  friction  is  depriving  us 
of  the  advantage  of  the  great  head  of  water.  The  channels 
of  communication  from  spring  B  are  free  and  large.  One 
may,  however,  be  deceived  unless  the  test  of  pumping  is  a 
prolonged  one.  What  is  known  as  a  '  pocket  of  water  ' 
may  appear  from  temporary  pumping  to  be  a  spring  of  the 
B  class;  but  sustained  pumping  will  demonstrate  the 
impostor,  as  the  water  level  will  not  recover  itself  without 
a  more  or  less  prolonged  period  of  rest.  This  proves  that 
while  the  channels  of  communication  are  large,  the  area 
which  is  being  drawn  from  is  small.  Under  such  circum- 
stances a  multiplication  of  wells  would  be  of  no  advantage; 
but  in  many  instances  th©  friction  of  drawing  water 
through  the  earth  may  be  largely  diminished  by  sinking 
a  number  of  tubes  and  coupling  them  together,  so  that  one 
pump  draws  from  them.  What  is  known  as  the  '  cone  of 
depression '  is  reduced  by  this  method  of  drawing  the 


378  WATER  SUPPLIES 

water.  Tubes  placed,  say,  20  feet  apart,  may  each  only 
yield  a  small  supply;  but  the  aggregate  obtained  from  a 
number  of  these  tubes  becomes  very  large. 

"  At  the  Burton  Breweries,  some  forty  or  fifty  3-inch 
'  Abyssinian  '  tube  wells  yield  2,000,000  gallons  daily ;  yet 
no  one  of  the  3-inch  tubes  delivers  more  than  2,000  gallons 
per  hour.  The  area  from  which  they  draw  is  so  extended 
that  at  no  one  point  is  the  water  level  materially  depressed. 

"  At  the  Town  Waterworks  of  Watford,  a  dug  well  of  10 
feet  diameter,  supplied  by  a  12-inch  boring  at  the  bottom 
of  it,  proved  inadequate  when  drawn  from  night  and  day 
to  meet  the  requirements  of  the  town.  A  single  tube  well 
of  8J  inches  in  diameter,  placed  some  30  feet  from  the  dug 
well,  doubled  the  supply  of  water  obtainable,  and  thus 
enabled  the  hours  of  pumping  to  be  materially  reduced. 
Somewhat  similar  experiences  were  obtained  at  the  Town 
Waterworks  of  Aldershot,  Hertford,  St.  Albans,  and  Abbots 
Langley,  all  of  which  towns  now  derive  their  water  supply 
from  tube  wells." 

The  imperfect  construction  of  many  of  our  older  wells 
to  some  extent  brought  boring  into  disrepute.  Thin  sheet- 
iron  was  in  many  districts  used  for  lining  the  bore.  The 
imperfect  joints  very  frequently  admitted  of  the  entrance  of 
subsoil  water,  hence  the  water  yielded  was  often  polluted. 
In  a  comparatively  few  years  the  sides  of  the  tubes  corroded 
and  collapsed,  and  the  supply  gradually,  or,  in  some  cases, 
suddenly  failed.  By  the  use  of  proper  casing,  such  as  the 
"  Russian  Brand  "  swelled  and  collar-joint  casing,  employed 
now  so  extensively,  all  these  defects  are  obviated.  The 
difficulty,  however,  of  making  these  tubes  absolutely  water- 
tight is  greater  than  at  first  would  be  anticipated,  and 
where  the  slightest  defect  exists  the  continued  raising  of 
water  by  pumps  fixed  directly  upon  the  bore  tube  is  very 
likely  to  accentuate  it  by  the  continued  lateral  insuction 
of  air  and  water.  A  most  instructive  example  of  such  a 
Defect  is  contained  in  Dr.  Geo.  Turner's  Report  on  the  Water 


WELLS  AND  THEIR  CONSTRUCTION  379 

Supply  to  the  Suffolk  County  Lunatic  Asylum,  previously 
referred  to.  Some  years  ago  the  prevalence  of  dysentery 
in  this  Asylum  was  attributed  to  the  impure  water  supply, 
and  a  fresh  supply  was  obtained  from  two  bored  wells,  so 
constructed  that  contamination  of  the  water  appeared  quite 
impossible.  Dr.  Turner  says,  "  The  construction  of  these 
bores  is  very  similar  in  principle,  but  varies  slightly  in 
detail.  In  both  instances  an  8-inch  steel  pipe  with  screw 
joints  was  sunk  into  the  chalk,  the  bore  was  then  enlarged, 
filled  with  cement,  and  the  8-inch  tube  sunk  into  the 
cement,  which  was  then  allowed  to  set.  After  the  cement 
had  set,  a  6-inch  steel  tube,  also  with  screw  joints,  was 
passed  through  the  cement  to  a  distance  of  200  feet,  when 
the  bore  was  again  enlarged;  the  cavity  was  filled  with 
cement,  which  was  allowed  to  set,  and  then  the  boring  was 
continued  another  100  feet.  The  total  depth  of  the  bores 
was  305  and  350  feet  respectively.  The  space  between  the 
8-inch  and  6-inch  tubes  was  filled  with  cement  through  a 
composition  pipe  passed  to  the  bottom,  and  the  bore  was 
fastened  to  the  pump  by  an  air-tight  joint."  Notwith- 
standing these  elaborate  precautions,  dysentery  again  broke 
out  in  the  Asylum,  and  was  again  traced  to  the  water 
supply.  Dr.  Turner  found  that  after  continued  pumping 
there  was  a  marked  difference  in  the  quality  of  the  water 
drawn  from  the  two  wells,  and  upon  excavating  around  the 
tubes  and  pouring  into  the  excavation  a  solution  of  chloride 
of  lithium,  he  afterwards  found  distinct  traces  of  this  salt 
in  the  water  drawn  from  the  pumps.  From  the-  result  of 
these  and  other  experiments  he  concluded  that  there  was 
no  reasonable  doubt  that  neither  of  the  tubes  was  water- 
tight. The  danger  of  lateral  insuction  must  be  greater  in 
wells  in  which  the  pump  is  screwed  directly  on  to  the  lining 
tube,  than  in  those  in  which  the  pump  pipe  or  barrel  is 
merely  inserted  within  the  lining  tube,  since  the  removal 
of  the  atmospheric  pressure,  in  the  former  case,  causes 
water  or  air  to  enter  the  bore  through  the  most  minute 


WATER  SUPPLIES 


apertures,  and  in  course  of  time  such  apertures  enlarge, 
admitting  impurities  more  and  more  freely.  This  danger, 
in  some  degree,  counterbalances  the  advantages  of  the 
increased  supply,  and  it  would  appear  to  be  safer  not  to 
directly  connect  the  pump  with  the  bore  tube  where  water 
can  be  obtained  in  sufficient  quantity  without  such  attach- 
ment. 

The  cost  of  constructing  bored  wells  varies  with  the 
nature  of  the  strata  which  have  to  be  pierced.  Fifty  years 
ago,  local  well-sinkers  in  Essex  would  pierce  300  feet  of 
London  clay,  line  the  well,  and  fix  a  pump  for  a  total  cost 
of  less  than  £100.  At  the  present  time  similar  wells  cost 
about  three  times  that  amount,  and  the  local  well-sinker 
has  disappeared.  The  only  explanation  appears  to  be  that 
it  has  been  found  more  economical  to  employ  pro- 
fessional well-borers,  and  pay  treble  the  price  for  a 
properly-constructed  well,  than  to  employ  the  local  men. 
Sir  R.  Rawlinson,  in  his  Official  Report  to  the  Local 
Government  Board  on  Water  Supplies,  etc.,  gives  the  follow- 
ing schedule  of  prices  for  making  bore-holes  in  red 
sandstone.  The  prices  for  boring  in  chalk  and  in  sand 
and  clay  average  Is.  per  foot  less,  but  in  sand  and  clay, 
where  the  boring  exceeds  200  feet  in  depth,  the  price  is, 
on  the  contrary,  about  3s.  per  foot  more  than  for  boring  in 
chalk  or  sandstone. 


Per  Foot  Run. 

Diameter. 
Inches. 

Cost  of  Cast  or 
Wrought-iron 
Pipes  per  Foot. 

First 
100  Feet. 

Second 
100  Feet. 

Third 
100  Feet. 

Fourth 

100  Feet. 

3  or  4 

5s.  6d. 

7s.  6d. 

11s.  6d. 

14s.  6d. 

4s.  to  5s.  6d. 

5 

7s.  6d. 

10s.  6d. 

13s.  6d. 

20s.  6d. 

6s.  6d. 

6 

8s.  6d. 

11s.  6d. 

14s.  6d. 

20s.  6d. 

7s.  6d. 

8 

9s.  6d. 

12s.  6d. 

16s.  6d. 

22s.  6d. 

10s.  6d. 

9 

12s.  6d. 

15s.  6d. 

20s.  6d. 

25s.  6d. 

11s.  6d. 

10 

13s.  6d. 

16s.  6d. 

21s.  6d. 

26s.  6d. 

13s. 

12 

17s.  6d. 

21s.  6d. 

25s.  6d. 

30s.  6d. 

18s.  6d. 

WELLS  AND  THEIR  CONSTRUCTION 


381 


The  following  schedule  of  prices  for  borings  from  the 
surface  from  3  to  12  inches  in  diameter,  is  exclusive  of 
lining  tubes  but  includes  all  labour  and  necessary  plant. 
The  prices  quoted  are  per  foot. 


Messrs.  Le  Grand  and 
Sutcliff. 

C.  Isler  and  Co.        + 

Boring  in 
Alluvial  and 
other  Free- 
boring  Strata. 

In  blowing 
Sand,  Rock, 
Stone,  and 
other  hard 
or  difficult 
Strata. 

Gravel,  Clay, 
Sand,  or  other 
soft  Strata. 

Rock  or 
Stone. 

Not  exceeding  100  ft. 
200  ft. 
300ft. 
400  ft. 
500  ft. 

7s.  to  14s. 
12s.  to  24s. 
16s.  to  30s. 
20s.  to  40s. 
30s.  to  50s. 

15s.  to  50s. 
20s.  to  70s. 
25s.  to  70s. 
30s.  to  80s. 
35s.  to  90s. 

8s.  to  20s. 
13s.  to  30s. 
18s.  to  40s. 
23s.  to  50s. 
28s.  to  60s. 

20s.  to  40s. 
25s.  to  50s. 
30s.  to  60s. 
35s.  to  70s. 
40s.  to  80s. 

The  wrought-iron,  lap-welded,  steel-socketed  tubes  vary 
in  price  with  the  fluctuations  of  the  market,  but  the 
following  are  recent  estimates :  — 

3-inch  internal  diameter,  J  inch  thick,  4s.  per  foot 

4  „  „  „  „      5s. 

6  „  „        T%-  „      9s.  to  10s. 

7i          „  „  „  „    Us.  to  13s. 

8^-inch  diameter  and  &  inch  thick,  15s.  to  17s.        „ 
10  „  „  „      18s.  to  20s. 

11£  „  §  „      23s.  to  25s. 

The  approximate  depth  at  which  water  may  be  reasonably 
expected  to  be  found,  and  the  nature  of  the  strata  to  be 
penetrated,  being  known,  the  cost  of  constructing  a  bored 
well  can  be  ascertained  from  the  above  data.  An  estimate 
of  the  amount  of  water  which  the  well  will  yield  can  only 
be  given  by  those  who  have  made  a  special  study  of  the 
hydrology  of  the  district. 

The  tables  on  pp.  383-4  give  the  details  of  a  number  of 


382  WATER  SUPPLIES 

typical  wells  bored  during  recent  years  by  Messrs.  Le  Grand 
and  Sutcliff. 

As  the  temperature  of  the  earth's  crust  increases  as  we 
descend,  it  follows  that  water  taken  from  a  great  depth 
must  have  a  higher  temperature  than  water  from  shallower 
wells.  The  increase  in  temperature  has  been  found  to  vary 
somewhat  considerably  in  different  localities,  but  1°  F.  for 
every  50  feet  to  60  feet  descended  is  a  fair  average.  A  well 
1,000  feet  deep,  therefore,  may  be  expected  to  yield  a  water 
having  a  temperature  16°  to  20°  higher  than  that  of  the 
subsoil  water  in  the  same  locality,  so  warm  in  fact  as  to 
be  decidedly  unpalatable.  In  some  countries  the  water 
obtained  is  quite  hot.  Thus,  in  Queensland,  some  of  the 
recently  sunk  deep  bores  yield  waters  having  a  temperature 
of  from  162°  to  175°  F.,  the  average  of  a  number  of  wells 
being  over  100°  F. 

In  all  cases,  before  deciding  upon  boring  for  water,  an 
expert  hydro-geologist  should  be  consulted,  otherwise  the 
experiment  may  prove  a  costly  failure.  Even  the  most 
experienced  expert  may  at  times  be  at  fault.  Neither  the 
quality  nor  the  quantity  of  water  obtainable  can  be 
invariably  predicted.  The  supply  obtainable  may  be 
increased  in  various  ways.  By  driving  two  or  more  tubes, 
and  connecting  the  various  wells  to  a  main  leading  to  the 
pump,  the  area  drawn  from  is  increased.  This,  however, 
seriously  augments  the  expense,  and  unfortunately  is 
not  always  successful.  Thus,  at  Liverpool,  where  sixteen 
bores  had  been  made  from  the  bottom  of  one  well, 
Mr.  Stephenson  found  that  the  yield  of  the  whole  was 
1,034,000  gallons  per  day,  whilst  from  a  single  bore-hole, 
the  other  fifteen  being  plugged,  the  yield  was  921,000 
gallons.  In  this  case,  of  course,  the  bores  were  much  too 
near  together.  By  placing  the  pump  barrel  at  a  greater 
depth  in  the  well,  more  water  may  be  obtained.  In  London 
the  long  barrel-pumps  are  fixed  at  depths  varying  from  200 
to  300  feet.  The  usual  plan  is  to  place  them  about  50  feet 


WELLS  AND  THEIR  CONSTRUCTION 


383 


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02  O  PH  O2  H  C/2 

WELLS  AND  THEIR  CONSTRUCTION  385 

below  the  water  level,  so  that  pumping  may  go  on  con- 
tinuously, if  necessary,  until  the  head  of  water  has  been 
reduced  about  80  feet.  Recently  most  successful  attempts 
have  been  made  to  increase  the  flow  through  closely-jointed 
rocks,  by  exploding  a  charge  of  dynamite  -or  blasting 
gelatine  at  the  bottom  of  the  well.  The  explosion  shatters 
the  surrounding  rock  and  opens  out  the  fissures  through 
which  the  water  pours.  At  Rochester  a  well  had  been 
sunk  to  a  depth  of  over  300  feet  without  finding  water. 
Messrs.  Isler  and  Company  placed  a  charge  of  gelatine, 
weighing  18  lb.,  at  a  depth  of  307  feet,  and  exploded  it. 
The  result  was  an  abundant  supply  of  water,  the  well 
yielding  afterwards  some  20,000  gallons  per  hour.  The 
proportion  of  unsuccessful  borings  in  England  is  probably 
very  inconsiderable,  but  no>  data  are  available  upon  which 
to  base  a  reliable  estimate.  In  several  of  our  colonies, 
where  well-sinking  is  being  undertaken  by  the  respective 
governments,  some  interesting  information  on  this  and  other 
points  is  given  in  the  engineers'  reports.  The  following 
brief  account  of  the  results  of  boring  operations  in  our 
colonies,  is  compiled  from  various  blue-books  issued  during 
recent  years  by  the  respective  governments. 

Queensland. — During  the  last  few  years  many  wells  have 
been  bored  by  the  Government  under  the  supervision  of 
the  official  hydraulic  engineer.  The  number  of  successful 
bores  during  the  past  eight  years  (1892-1900)  appears  to  be 
424,  and  the  cost  about  £1,000,000.  Three  hundred  of 
these  wells  overflow,  yielding  over  190  million  gallons  of 
water  daily.  All  the  borings  made  have  not  been  success- 
ful; in  some  instances  no  water  was  found,  in  others  the 
water  was  not  fit  for  domestic  purposes,  and  some  bores 
were  abandoned  for  other  reasons.  The  chief  wells  are  :  — 


386 


WATER  SUPPLIES 


District.. 

Depth. 

Yield  per  Day. 

Temp,  of 
Water. 

Cost, 

Barcaldine    . 

691  ft. 

175,000  galls. 

102°  F. 

£1,340 

Blackall 

1,663  , 

300,000      „ 

119°  F. 

5,074 

Charleville    . 

1,571   , 

3,000,000      „ 

106°  F. 

3,525 

Cunnamulla 

1,402  , 

540,000     „ 

106°  F. 

2,316 

Muckadilla   . 

3,262  , 

23,000      „ 

124°  F. 

7,382 

"  65-mile  bore  " 

2,362  , 

104,000      „ 

3,073 

About  715  public  and  private  wells  have  been  sunk, 
varying  in  depth  from  86  to  2,484  feet.  The  number  of 
unsuccessful  borings  is  not  stated.  The  water  is  derived 
from  the  lower  cretaceous  formation,  and  most  of  the  wells 
overflow.  The  largest  yield  is  from  a  private  bore  in  the 
Warrego  district.  The  well  is  1,502  feet  deep,  and  yields 
3,500,000  gallons  of  water  daily  (112°  F.),  at  a  pressure  of 
200  Ib.  to  the  square  inch.  The  yield  at  the  present  time 
from  all  the  wells  is  estimated  at  over  200,000,000  gallons 
per  day.  The  flow  of  a  largfc  proportion  is  uncontrolled, 
and  most  of  it  wasted.  A  bill  was  recently  introduced  to 
regulate  the  flow  from  these  bores  and  prevent  the  lower- 
ing of  the  pressure  (water  level),  but  it  was  thrown  out  by 
the  Upper  House.  Regulating  valves  are  used  for  all  the 
Government  bores. 

In  South  Australia  it  is  estimated  that  the  area  of  the 
water-bearing  chalk  basin  is  nearly  100,000  square  miles; 
but  the  number  of  wells  bored  at  present  is  inconsiderable. 
Water  has  been  obtained  at  depths  varying  from  237  to 
1,220  feet,  the  temperature  ranging  from  81°  F.  to  90°  F., 
and  the  yield  from  48,000  to  1,200,000  gallons  daily.  In 
some  wells  the  water  rises  considerably  above  the  surface; 
in  others  it  does  not  reach  the  outlet  of  the  bore. 

In  the  Colony  of  Victoria  the  Government  has  expended 
some  £50,000  in  making  experimental  bores,  but  apparently 
with  little  success.  In  some  cases  the  rocks  were  pierced 
to  a  depth  of  over  2,000  feet  without  water  being  dis- 
covered ;  in  others  the  water  obtained  was  unfit  for  domestic 


WELLS  AND  THEIR  CONSTRUCTION  387 

purposes,  whilst  in  the  few  successful  bores  the  water  level 
was  far  below  the  ground  surface  and  the  supply  limited. 
One  instance  is  recorded  in  which  the  saline  constituents  of 
the  water  acted  so  powerfully  upon  the  iron  lining  of  the 
bore  as  to  destroy  its  continuity  within  eighteen  months. 

New  South  Wales. — In  1892  Mr.  Boultbee,  the  Offieer-in- 
Charge  for  Water  Conservation,  issued  a  report  on  Artesian 
boring,  containing  sections  and  descriptions  of  all  the 
Government  bores.  The  bores  when  decided  upon  are  let 
by  tender,  the  work  being  done  under  official  supervision. 
Mr.  Boultbee  gives  a  list  of  twelve  completed  borings,  and 
refers  to  40  other  bores  in  progress.  Particulars  are  also 
given  of  forty-five  private  bores.  The  wells  vary  in  depth 
from  53  to  2,000  feet.  Two  borings  appear  to  have  been 
unsuccessful ;  the  remainder  yield  from  24,000  to  2,000,000 
gallons  of  water  per  day.  Most  of  the  private  wells  are 
from  700  to  1,000  feet  deep,  and  the  flow  varies  from  nil 
to  1,728,000  gallons  daily.  The  tenders  for  the  Government 
bores  varied  from  24s.  to  27s.  per  foot  for  the  first  1,000 
feet;  from  27s.  6d.  to  32s.  6d.  for  the  next  500  feet,  and 
from  30s.  to  40s.  for  an  additional  500  feet,  exclusive  of 
casing.  The  contractor  finds  all  plant,  tools,  labour,  etc., 
but  the  Government  does  all  the  carting  and  supplies  the 
casing.  The  average  cost  of  the  bores  per  foot,  including 
casing,  is  said  to  be  37s.  All  the  Government  bores,  and 
some  of  the  private  bores,  have  valve  arrangements  for 
regulating  the  flow,  but  Mr.  Boultbee  believes  that  some 
16,000,000  gallons  of  Artesian  well  water  runs  daily  to 
waste,  and  he  recommends  legislation  to  prevent  this. 
Imperfect  casing  is  also  probably  the  cause  of  serious  waste, 
and  this  he  thinks  should  be  dealt  with  by  legislation,  as  is 
already  done  in  some  of  the  North  American  States. 
The  chalk  basin  yielding  water  is  estimated  to  have  an  area 
of  40,000  square  miles.  Over  the  catchment  area  supplying 
this  basin  the  average  rainfall  is  22  inches,  and  only  about 
1£  per  cent,  of  this  finds  its  way  into  the  rivers.  It 


388  WATER  SUPPLIES 

is  assumed,  therefore,  that  50  per  cent,  of  the  total 
rainfall  percolates  and  is  recoverable  by  means  of 
wells  and  bores.  As  the  catchment  area  is  only  about 
13,000  square  miles  in  extent,  the  water  from  the 
bores  should  not  be  sufficient  to  irrigate  more  than 
about  one-sixth  the  area  of  the  chalk  basin.  Mr. 
Boultbee  believes  that  if  further  operations  are  equally 
successful,  it  will  be  "  difficult  to  estimate  the  progress  and 
prosperity  that  must  naturally  ensue/'  The  few  analyses 
given  show  that  some  of  the  wells  yield  strongly  saline 
water,  and  others,  water  which  is  strongly  alkaline,  such  as 
is  derived  from  the  chalk  in  certain  portions  of  Essex.  The 
Government  Veterinarian,  reporting  on  saline  waters,  says, 
"It  is  easy  to  understand  that  starving,  or  even  thirsty 
travelling  stock  may  suffer  disastrously  from  drinking  at 
once  a  large  quantity  of  water  containing  a  high  percentage 
of  saline  material.  Horses  and  cattle  will  drink  from  5  to 
12  gallons  a  day,  sheep  from  1  to  2  gallons  a  day.  Drovers 
should  be  cautioned  at  saline  drinking-places  of  the  danger 
of  permitting  stock  to  drink  too  freely,  until  they  have 
become  accustomed  to  the  medicinal  properties  of  the 
water." 

Cape  of  Good  Hope. — The  Government  Inspector  of 
Water  Drills,  in  his  report  for  1893,  says  that  the  work 
undertaken  by  the  Government  has  been  an  unqualified 
success,  but  the  geological  formation  in  many  parts  of  the 
colony  is  such  as  not  to  be  "  conducive  to  the  existence  of 
Artesian  areas  of  any  great  extent.  A  great  portion  of  the 
colony,  known  as  the  Karoo>,  however,  contains  many  such 
areas,  and  here  prospecting  for  water  has  been  most 
successful.  This  district  is  composed  of  a  series  of  areas 
formed  by  a  network  of  intrusive  igneous  dykes,  chiefly 
of  a  dolerite  nature,  cutting  through  the  sandstone  and 
shales  and  acting  as  intercepting  barriers  to  the  under- 
ground water.  Since  the  commencement  of  operations  in 
May,  1891,  out  of  a  total  of  341  holes  bored,  water  was 


WELLS  AND  THEIR  CONSTRUCTION  389 

tapped    in    289    and    overflowed    from    128.     The    average 
depth  was  only  43  feet  per  hole,  and  the  deepest  bore  was 
only  227  feet.    The  flow  from  the  128  bore-holes  is  estimated 
at  2,332,000  gallons  daily,  or  an  average  of  about   18,000 
gallons  per  well.     In  several  cases  the  flow  has  decreased; 
in    others    it    has    increased.     The    Inspector    thinks    that 
there  is  little  fear  of  exhausting  the  underground  reservoirs, 
since    moderate-sized    towns,    such    as    Colesburg,    Victoria 
West,    Hanover,    Veuterstad,     and    Bristown,     "  boast    of 
perennial  streams,   issuing  from   one   or  two  bore-holes  in 
each  case,  sufficient  to  supply  their  domestic  wants  as  well 
as  to  irrigate  numerous  erven."     The  Inspector  recommends 
that  where  the  water  does  not  overflow,  4-inch  bores  should 
be  made  instead  of   2-inch   as   at  present,   and  to  such   a 
depth  as  will  ensure  a  50-feet  head  of  water  from  which  to 
pump.     With  a  deep-well  pump  and  windmill,  practically 
inexhaustible  supplies  could  be  obtained  from  such  wells 
at  a  nominal  cost.     A  few  very  deep  wells  have  been  bored 
(up  to  1,200  feet),  but  the  results  are  not  encouraging.     In 
Bushmanland   and  Bechuanaland,   where   the  general  geo- 
logical formation  is  gneiss  and  granite,  the  rock  can  only 
be  pierced  by  the  diamond  drill,  and  the  wear  and  tear  of 
the   diamonds  is  severe.     As   the   water  lies   in   the   rock 
fissures  at  but  a  slight  depth,  the  rock  is  better  penetrated 
by  means  of  blasting. 

In  the  United  States  a  special  Department  at  Washington 
collects  information  with  reference  to  all  wells  bored,  and 
in  several  states  Acts  have  been  passed  to  encourage  the 
sinking  of  Artesian  wells,  and  for  preventing  waste  of 
the  water  flowing  therefrom.  The  number  of  such  wells 
is  simply  enormous.  In  the  Utah  Territory  there  are 
nearly  2,000 ;  in  the  San  Joaquin  Valley,  California,  about 
3,000;  in  the  San  Louis  Valley,  2,000;  in  Deseret,  2,000, 
etc.  In  Kern  County,  California,  within  an  area  of  18  by 
14  miles,  there  is  a  group  of  wells  yielding  61,000,000 
gallons  of  water  daily.  To  the  development  of  well-boring 


3go  WATER  SUPPLIES 

the  reclamation  of  the  Great  American  Desert  is  in  great 
part  due.  Enormous  tracts  of  land,  over  which  the  annual 
rainfall  is  only  from  2  to  6  inches,  are  now  irrigated  by 
the  water  overflowing  from  Artesian  wells. 

In  Algeria  and  Sahara  the  French  engineers  have  during 
recent  years  been  engaged  in  reclaiming  the  deserts  by 
means  of  water  derived  from  deep  bores,  and  it  is  stated 
that  the  flow  from  the  wells  already  sunk  is  about 
100,000,000  gallons  daily,  and  that  the  effect  produced  upon 
the  sandhills  by  irrigation  is  amazing. 

In  Argentina  and  Uruguay  a  drilling  company  has 
recently  sunk  a  number  of  wells,  and  last  year  the  Buenos 
Ayres  and  Rosario  Railway  Company  drove  an  Abyssinian 
tube  well  to  a  depth  of  200  feet,  and  obtained  an  abundant 
supply  of  water. 

In  arid  regions,  and  where  the  rainfall  is  fitful,  water 
can  often  be  obtained  for  irrigation  purposes  by  boring, 
and  it  is  probable,  now  that  increased  attention  is  being 
drawn  to  this  method  of  obtaining  water,  many  districts 
at  present  uninhabitable  will  become  both  populous  and 
prosperous.  In  certain  of  our  Colonies  it  may  safely  be 
asserted  that  the  discovery  of  these  subterranean  sources 
of  water  will  ultimately  conduce  to  far  greater  prosperity 
than  the  discovery  of  gold. 

In  all  attempts  to  obtain  water  by  sinking  wells,  the 
following  facts  should  be  borne  in  mind.  Sand  or  gravel 
resting  on  chalk  will  yield  no>  water,  unless  the  chalk  also 
is  penetrated  to  below  the  plane  of  saturation;  that  chalk 
contains  immense  volumes  of  water,  but  almost  exclusively 
in  the  fissures.  Wells  or  borings  sunk  in  very  solid  chalk 
may  yield  no  water,  the  more  fissured  the  stratum  and  the 
greater  the  yield  that  may  be  anticipated.  The  tertiary 
sands  between  the  London  clay  and  the  chalk  yield  only  a 
moderate  quantity  of  water.  The  impermeable  beds  of 
Purbeck  and  Portland  stone  often  contain  a  considerable 
amount  of  water  in  their  fissures,  but  under  the  latter  rock 


WELLS  AND  THEIR  CONSTRUCTION  391 

water  may  be  found  in  the  porous  stratum  between  it 
and  the  elay  beneath.  Limestone  is  only  slightly  porous, 
and  the  water  contained  therein  is  probably  chiefly  found 
in  the  fissures.  The  lower  oolite  contains  large  quantities 
of  water  held  up  by  the  impervious  beds  of  the  lias.  In 
the  magnesian  limestone  water  is  only  found  where  fissures 
are  struck,  but  in  this  and  the  mountain  limestone  the 
water  may  be  very  abundant.  In  fissures  of  the  meta- 
morphic  rocks,  water  also  may  be  met  with  in  the  fissures 
if  the  sinking  or  boring  is  fortunate  enough  to  strike  such ; 
but  as  the  stratification  is  usually  very  irregular,  the  result 
of  a  boring  can  never  be  with  safety  predicted. 


CHAPTER  XXI. 
PUMPS  AND  PUMPING  MACHINERY. 

NUMEROUS  varieties  of  pumps  are  now  manufactured  for 
raising  water,  and  each  probably  possesses  some  advantages 
over  the  others  under  certain  conditions.  A  pump  which 
under  one  set  of  circumstances  will  work  effectively  and 
economically,  may  under  other  circumstances  be  ineffective 
or  extravagant.  Where  large  quantities  of  water  have 
to  be  raised,  the  selection  of  a  pump  is  of  the  highest 
importance,  and  it  is  only  when  the  duty  which  it  will 
have  to  perform  and  the  exact  conditions  under  which  it 
must  work  are  fully  known  that  the  selection  can  be 
satisfactorily  made.  All  the  varieties  in  ordinary  use  can 
be  classified  under  the  four  following  types — (a)  Lifting 
pumps,  (b)  Plunger  or  force  pumps,  (c)  Centrifugal  pumps, 
and  (d)  Air  Lift  pumps. 

(a)  The  commonest  form  of  pump,  the  atmospheric,  is 
the  simplest  form  of  this  type.  The  essentral  part  is  the 
barrel,  which  is  truly  cylindrical  and  carefully  bored  and 
closed  at  the  bottom  by  a  valve  opening  upwards.  Within 
the  barrel  works  a  piston  or  bucket,  fitting  the  cylinder 
accurately,  which  is  also  provided  with  a  valve  opening 
upwards.  When  the  piston  ascends,  the  atmospheric 
pressure  is  removed  from  the  surface  of  the  lower  valve, 
and  water  ascends  through  the  so-called  suction  pipe, 
ultimately  entering  the  pump  barrel.  When  the  piston 
descends  the  lower  valve  'doses,  and  the  water  is  forced 
through  the  valve  in  the  piston,  and  at  the  next  up-stroke 

(392) 


PUMPS  AND  PUMPING  MACHINERY  393 

is  discharged  from  the  pump.  The  height  at  which  the 
pump  barrel  may  be  fixed  above  the  surface  of  the  water 
to  be  raised  obviously  depends  chiefly  upon  the  atmospheric 
pressure.  At  sea-level  this  corresponds  to  a  column  of 
water  about  34  feet  high.  As  the  valves  and  piston,  even 
with  best  workmanship,  are  not  perfect,  such  a  pump  cannot 
be  depended  upon  to  raise  the  water  more  than  27  feet. 
The  vertical  distance  between  the  level  of  the  water  to  be 
raised  and  the  highest  point  reached  by  the  piston  must 
not,  therefore,  exceed  this  distance.  Where  the  water-level 
fluctuates  care  must  be  taken  to  measure  from  the  lowest 
level  reached  during  these  fluctuations,  otherwise  the  water 
may  at  times  fall  so  low  that  the  pump  will  cease  to  act. 
This  form  of  pump  is  only  suitable  for  hand  power  and  for 
use  where  it  is  not  inconvenient  to  raise  the  water  as 
required.  For  shallow  wells  it  is  almost  universally 
employed,  the  water  discharged  from  the  pump  barrel 
passing  directly  or  through  a  very  small  reservoir  to  the 
outlet.  In  another  form  the  upper  portion  of  the  body  of 
the  pump  is  elongated,  or  a  pipe  is  connected  therewith, 
into  which  the  water  rises  with  every  stroke  of  the  piston. 
As  each  stroke  not  only  has  to  overcome  the  atmospheric 
pressure,  but  has  also  to  raise  this  column  of  water,  it  is 
evident  that  the  height  to  which  water  can  be  so  raised  by 
hand  power  is  limited.  About  30  feet  is  the  highest  to 
which  water  can  be  conveniently  raised  by  one  man.  When 
other  motive  power  is  employed  it  may  be  raised  by  such  a 
pump  to  about  100  feet  above  its  source.  This  limit,  in 
actual  practice,  is  probably  due  to  several  causes,  of  which 
the  principal  is  the  uncertain  action  of  the  piston  valve 
under  such  great  pressure.  In  deep  wells,  where  the  water- 
level  is  more  than  24  or  25  feet  from  the  surface  of  the 
ground,  the  pump  must  be  fixed  within  the  well,  the  piston 
rod  being  lengthened  so  as  to  be  connected  with  a  lever 
or  handle,  or  to  a  fly-wheel.  In  such  cases  it  is  usual  to 
fix  a  double-barrel  pump,  since  it  is  easier  to  raise  a  given 


394  WATER  SUPPLIES 

volume  of  water  with  such  a  pump  than  with  a  single- 
barrel  of  capacity  equal  to  the  two  together.  With  the 
double-barrel  the  work  is  distributed,  each  half-turn  raising 
one  piston,  whereas,  with  the  single-barrel  the  whole  lift 
is  on  one  half  turn.  With  a  treble  pump  the  work  is  still 
more  equally  distributed;  but  as  complications  are  intro- 
duced the  double-barrel  is  generally  preferred. 

The  pump  need  not  be  fixed  over  or  even  near  the  well ; 
but  if  at  any  considerable  distance,  it  must  be  remembered 
that  a  certain  amount  of  friction  is  introduced,  and  must 
be  allowed  for.  The  suction  pipe  must  fall  all  the  way 
from  the  pump  to  the  well,  otherwise  air  may  lodge  in  the 
bends  and  impair  the  action  of  the  pump.  In  long  suction 
pipes  it  is  desirable  to  have  a  foot  valve  to  retain  the  water 
when  the  pump  is  not  in  use,,  and  to  prevent  the  concussion 
caused  by  the  sudden  arrest  of  the  motion  of  the  long 
column  of  water  at  each  down-stroke  of  the  piston ;  a 
vacuum  vessel  also  should  be  connected  with  the  pipe  just 
before  it  enters  the  pump. 

In  another  form  of  lift  pump  a  solid  piston  plays  in  a 
barrel  placed  alongside  a  second  barrel,  which  is  closed  at 
each  end  by  a  valve  opening  upwards.  The  upper  end  of 
this  second  cylinder  is  continuous  with  the  rising  main, 
whilst  the  lower  end  is  continued  into  the  suction  pipe. 
The  upper  end  of  the  pump  barrel  is  connected  by  a  wide 
tube  with  the  valve  cylinder.  When  the  pump  is  in  action 
depression  of  the  piston  causes  a  vacuum  in  the  barrel 
within  which  it  works,  into  which  water  rises  through  the 
valve  at  the  upper  end  of  the  suction  pipe.  When  the 
piston  is  raised  this  water  is  forced  through  the  upper  valve 
into  the  rising  main.  A  pump  of  this  character  can  raise 
water  a  height  of  700  feet  and  upwards. 

(6)  In  the  plunger  or  force  pump  a  solid  plunger  takes  the 
place  of  the  ordinary  piston  or  bucket,  but  the  suction  pipe, 
valves,  and  rising  main  resemble  in  arrangement  the  pump 
just  described.  The  cylinder,  however,  in  which  the 


PUMPS  AND  PUMPING  MACHINERY  395 

plunger  works  is  connected  with  the  valve  box  by  an 
opening  near  its  base,  and  the  plunger  does  not  accurately 
fit  the  cylinder  in  which  it  works.  When  pumping  is  in 
operation  the  water  rises  in  the  suction  pipe  to  fill  the 
vacuum  produced  by  the  rising  plunger,  and  when  this 
falls  it  forces  into  the  rising  main  an  amount  of  water 
equal  to  the  volume  of  the  plunger  which  enters  the 
cylinder.  This  single-acting  plunger  pump  is  largely 
employed  for  raising  water  to  considerable  heights.  It  is 
obvious  that  in  this  form  of  pump  also  the  vertical  length 
of  the  suction  pipe  must  not  exceed  27  feet.  As  a  matter 
of  practice  the  pump  barrel  is  usually  only  a  few  feet  above 
the  surface  of  the  water  to  be  raised.  Two  or  three  such 
pumps  may  be  combined,  and  so  arranged  that  the 
discharge,  instead  of  being  intermittent,  as  in  the  single- 
barrel  pump,  becomes  practically  continuous.  For  high 
lifts  and  heavy  pressures  air  chambers  must  be  connected 
-with  these  pumps.  The  water  being  forced  into  these 
instead  of  directly  into  the  main,  the  compressed  air  acts 
as  a  cushion,  and  tends  greatly  to  equalise  the  flow  of 
water  and  relieve  the  valves  from  undue  shock.  The  force 
pump  is  less  troublesome  to  keep  in  repair  than  the  lift 
pump,  since  it  dispenses  with  the  bucket,  the  clack  valve 
of  which  can  only  be  reached  for  repairs  by  taking  the 
pump  to  pieces.  Whilst  the  pump  barrels  are  usually 
fixed  vertically,  they  are  occasionally  placed  in  a  horizontal 
position.  In  waterworks  where  water  has  to  be  raised  from 
a  well,  and  then  forced  to  a  considerable  elevation,  usually 
two  sets  of  pumps  are  employed,  one  raising  the  water  from 
the  well  to  a  reservoir  at  or  near  the  ground-level,  and  the 
other  forcing  the  water  from  this  reservoir  to  the  highest 
point  at  which  the  water  is  required. 

(<arand  b)  The  so-called  bucket  and  plunger  pump,  which 
is  probably  most  extensively  used  for  high  lifts,  combines 
in  its  construction  both  principles  a  and  6,  acting  both  as  a 
lift  and  plunger  pump.  The  piston  rod  working  within 


3g6  WATER  SUPPLIES 

the  pump  barrel  has  a  cross  section  half  that  of  the  bucket 
or  cylinder,  otherwise  in  construction  it  resembles  the 
ordinary  lift  pump.  When  in  action  the  down-stroke  of 
the  piston  forces  the  water  through  the  bucket  valve ;  but 
as  half  the  volume  of  the  cylinder  is  occupied  by  the  piston, 
half  the  water  is  forced  into  the  rising  main.  With  the 
up-stroke  the  other  half  passes  into  the  main,  whilst  the 
barrel  under  the  piston  is  again  filling  from  the  suction 
pipe.  It  is  practically,  therefore,  a  double-action  pump, 
performing  with  one  set  of  valves  the  work  of  two  smaller 
pumps. 

Other  combinations  of  these  two  classes  of  pump  are 
made,  each  manufacturer  claiming  some  advantage  for  his 
special  construction. 

The  Glenfield  Company,  of  Kilmarnock,  have  recently 
introduced  a  pump  invented  by  Mr.  Henry  Ashley,  in 
which  there  is  no  bottom  clack,  the  suction  and  delivery 
valves  both  being  in  the  bucket.  The  advantages  of  this 
pump  are  greater  accessibility  to  the  working  parts,  an 
important  matter  in  deep  wells,  and  quicker  running, 
allowing  of  smaller  pumps  being  used.  These  pumps  are 
being  used  at  the  Brighton  Corporation  Waterworks  and 
at  the  East  London  Waterworks. 

(c)  Centrifugal  Pumps. — These  pumps  differ  entirely 
from  either  of  the  types  just  described,  inasmuch  as  they 
contain  no  valves  or  pistons.  A  series  of  fans  or  blades 
are  attached  to  a  spindle,  passing  through  the  centre  of  a 
cast-iron  case  in  which  they  are  contained.  By  the 
revolution  of  these  fans  a  partial  vacuum  is  produced 
behind,  into  which  the  water  is  drawn,  or  rather  forced  by 
the  pressure  of  the  atmosphere,  whilst  the  water  in  front 
of  the  blades  is  forced  into  the  rising  main.  The  efficiency 
of  such  pumps  depends  chiefly  upon  the  degree  to  which 
fluid  friction  and  shock,  from  impact  of  the  blades  upon 
the  water,  can  be  reduced,  and  these  again  depend  upon 
the  mode  in  which  the  water  enters  the  pump,  and  upon 


PUMPS  AND  PUMPING  MACHINERY 


397 


the  curvature  and  arrangement  of  the  blades.  These  pumps 
are  not  suitable  for  raising  water  to  any  considerable 
height.  Up  to  about  25  feet  they  are  probably  more 
effective  than  any  other  form  of  pump,  but  above  30  feet 
a  good  plunger  pump  will  give  better  results.  Centrifugal 
pumps  are  made  capable  of  raising  water  over  100  feet,  and 
as  they  are  more  simple  and  compact  than  other  types,  these 
advantages  may,  under  certain  circumstances,  more  than 
compensate  for  the  larger  amount  of  fuel  consumed  when 
water  has  to  be  raised  more  than  30  feet.  The  advantages 
of  this  type  as  compared  with  either  of  the  preceding  may 
be  summarised  as  under  :  — 


FIG.  21. — Centrifugal  Pump.     A,  rising  main  ;  B,  suction  pipe. 

1.  There  being  no  vibration  or  oscillation,  a  lighter  and 

less  expensive  foundation  is  required. 

2.  They  are  more  easily  and  readily  fixed  and  repaired. 

3.  Greater  simplicity  of  construction,  and  greater  dura- 

bility  from   the   absence   of   valves,    eccentrics,    air- 
vessels,  etc. 

4.  Less  affected  by  sand  or  grit. 

5.  Moderate  cost,  and  up  to  a  certain  point  the  greater 

efficiency  measured  by  (a)  the  power  employed,  (b) 
the  quantity  of  water  raised,  (c)  the  height  to  which 
it  is  raised,  and  (d)  the  time  required  to  raise  it. 
(d)   From  America  we  have  had  introduced  the  Air  Lift 


398 


WATER  SUPPLIES 


Pump,  which  has  certain  advantages  for  deep  well  work, 
especially  where  sand  is  raised  in  the  water.  There  are 
no  valves  or  mechanical  parts  of  any  kind.  The  pump 
consists  of  a  water  pipe  and  an  air  pipe,  the  latter  dis- 
charging compressed  air  into  the  former  at  its  bottom. 
The  air  rises  in  the  water  pipe,  carrying  the  water  with  it 
in  short  detached  columns.  Compressed  air  for  pumping 
purposes  is  largely  used  in  America,  and  several  installations 
have  recently  been  made  in  this  country. 

Another  very  useful  pump  where  the  water  has  only  to 
be  lifted  a  few  feet  is  the  "Pulsometer."  This  pump  con- 
tains neither  bucket  nor  plunger,  the  vacuum  into  which 
the  water  rises  by  air  pressure  being  produced  by  the 
condensation  of  steam. 

Theoretically  the  amount  of  water  raised  by  a  lift  pump 
in  a  given  time  depends  upon  the  diameter  of  the  pump 
cylinder,  the  length  of  the  stroke  of  the  piston,  and  the 
number  of  strokes,  whilst  in  the  plunger  type  the  diameter 
of  the  plunger  must  be  substituted  for  that  of  the  cylinder. 
For  convenience  of  calculation  the  following  table  gives 
the  amount  of  water  in  gallons  delivered  per  inch  of 
stroke  in  pumps  with  cylinders  or  plungers  of  various 
diameters :  — 


Diameter  of  Cylinder 
or  Plunger. 

Gallons  of  Water  delivered  per 
each  Inch  of  Stroke  of  Pump. 

2J  inches 

•0176 

2f 

•0212 

3 

•0254 

1 

•0298 
•0398 

4 

•0454 

5 

•0708 

6 

•1020 

8 

•1816 

12 

•4080 

PUMPS  AND  PUMPING  MACHINERY  399 

To  find  the  theoretical  quantity  of  water  raised  per 
minute  by  a  given  pump,  multiply  the  quantity  delivered 
per  inch  stroke  corresponding  with  the  diameter  of  the 
cylinder  or  plunger  by  the  length  of  the  stroke  and  the 
number  of  strokes  per  minute.  For  example,  a  pump  with 
4-inch  cylinder,  10-inch  stroke,  and  working  at  30  strokes 
per  minute,  should  deliver 

•0454  x  10  x  30  =  13-62  gallons  per  minute. 

If  such  a  pump  actually  delivered  this  amount  of  water  its 
action  would  be  perfect,  and  its  modulus  of  efficiency  would 
be  considered  as  100.  In  actual  practice  such  an  efficiency 
is  never  reached.  The  common  lift  pump  has  usually  only 
an  efficiency  of  about  50 ;  ordinary  plunger  pumps  of  from 
60  to  70,  whilst  the  highest  class  of  waterwork  pump  often 
does  not  exceed  80.  The  efficiency  of  centrifugal  pumps 
varies  widely  with  the  conditions  under  which  they  are 
used,  and  under  favourable  circumstances  may  not  exceed 
50  per  cent,  of  the  theoretical  amount. 

The  degree  of  efficiency  attained  is  an  index  of  the 
quality  of  the  machine  turned  out  by  the  maker;  but  it 
varies  with  the  construction  of  the  pump,  and  one  form  may 
show  a  higher  efficiency  when  working  at  a  certain  speed 
and  doing  a  certain  duty,  whilst  another  may  excel  it  at  a 
different  speed  and  duty.  Unnecessary  friction  is  intro- 
duced and  efficiency  impaired  if  the  suction  and  delivery 
pipes  be  too  small,  or  have  sharp  bends  along  their  course. 
The  delivery  pipe  should  have  a  diameter  at  least  half  that 
of  the  pump  barrel,  and  the  suction  pipe  should  be  still 
wider.  In  the  latter  the  atmospheric  pressure  alone  has 
to  raise  the  water  against  the  force  of  gravity  and  has  to 
overcome  the  friction,  whereas  in  the  former  these  are 
effected  by  the  power  used  to  work  the  pump. 

Water  may  be  raised  by  means  of  /pumps  by  manual 
labour,  by  labour  of  some  animal,  horse,  pony,  ox,  mule 
or  ass,  by  aid  of  the  wind  or  falling  water,  or  by  steam, 


400  WATER  SUPPLIES 

hot-air,  gas,  or  oil  engines.  Electrical  pumps  also  are  now 
in  use. 

For  small  and  intermittent  supplies,  where  the  water 
has  only  to  be  raised  to  an  inconsiderable  height,  human 
labour  must  often  be  depended  upon ;  but  both  human  and 
animal  labour  is  often  used  when  wind  or  water  power 
could  be  profitably  utilised,  and  even  where  some  form  of 
gas  or  oil  engine  would  be  more  economical. 

Hand  labour  may  be  employed  in  pumping,  either  in 
working  a  pump  handle  or  in  the  continuous  turning  of  a 
crank  and  handle.  In  the  ordinary  pump  the  leverage 
is  usually  about  6  to  1,  i.e.,  the  distance  from  the  fulcrum  to 
the  free  end  of  the  handle  is  about  six  times  that  of  the 
fulcrum  to  the  point  of  attachment  of  the  handle  to  the 
piston  rod.  With  a  crank  and  handle  the  leverage  varies 
from  3  to  1  to  4  to  1,  according  to  the  length  of  the  stroke 
and  the  diameter  of  the  circle  described  by  the  handle. 
Whilst  the  latter  is  pleasanter  to>  work,  it  is  evident  that 
a  man  exercises  more  power  with  the  former.  With  the 
pump,  the  whole  or  nearly  the  whole  of  the  force  is  exerted 
in  depressing  the  handle,  whereas  with  a  crank  and  fly- 
wheel the  work  is  more  equalised.  With  a  single-barrel 
pump  the  pump  handle  or  the  fly-wheel  can  be  so  weighted 
as  to  render  the  work  in  the  up-stroke  and  down-stroke 
more  nearly  equal.  If  the  well  frame  be  provided  with  a 
wheel  and  pinion  the  power  required  to  raise  water  a  given 
distance  can  be  diminished  in  any  "ratio ;  but  the  amount 
of  water  raised  by  each  revolution  of  the  handle  is 
diminished  in  the  same  proportion,  or,  in  other  words,  what 
is  gained  in  power  is  lost  in  time.  It  is  easier  to  raise  a 
given  quantity  of  water  with  a  double-barrel  pump  than 
with  a  single-barrel  pump  of  a  capacity  equal  to  the  two 
barrels,  since  with  the  former  half  the  water  is  raised  with 
each  half  turn,  whereas,  with  the  latter  the  whole  is  raised 
at  one  half  turn. 

The  resistance  to  be  overcome  in  raising  water  any  given 


PUMPS  AND  PUMPING  MACHINERY 


401 


height  will  be  the  weight  of  a  column  of  water  of  that 
height  and  of  cross  section  equal  to  that  of  the  pump  piston, 
plus  the  resistance  due  to  friction  and  the  weight  of  the 
pump  rods.  The  following  table  admits  of  the  water 
pressure  being  readily  calculated :  — 


Diameter  of  Pump  Cylinder. 

Weight  of  Corresponding  Column 
of  Water  10  Feet  High. 

2  inches 
3       !,' 

5       " 
6       „ 

13-6  Ib. 
21-2 
30-6 
41-6 
54-4 
85-0 
122-4 

Example. — Required  the  water  pressure  upon  a  piston  of 
3  inches  diameter  raising  water  to  a  height  of  80  feet. 
Since  from  the  table  a  column  of  water  3  inches  in  diameter 
and  10  feet  long  weighs  30.6  Ib.,  the  pressure  of  a  column 
80  feet  long  will  be  244.8  Ib.  The  above  weight  includes 
that  of  the  column  of  water  raised  by  the  atmospheric 
pressure,  since  the  piston  is  raised  against  this  pressure. 
With  an  ordinary  pump,  having  a  handle  with  leverage  of 
6  to  1,  a  force  of  ?^18=  40.8  Ib.  would  have  to  be  applied  to 
raise  the  water  alone  without  allowing  for  friction,  etc. 
By  the  use  of  a  wheel  and  pinion  this  power  could  be  reduced 
so  as  to  enable  one  man  to  raise  the  water,  the  power  which 
an  ordinary  labourer  is  able  continuously  to  employ  for 
such  a  purpose  being  only  25  Ib.  From  the  above  table  the 
height  to  which  one  or  more  men  can  raise  water  by  means 
of  a  pump  worked  either  by  a  handle  or  crank  can  be 
determined  approximately,  if  the  effect  due  to  friction  be 
not  excessive. 

The  following  table,  by  Molesworth,  gives  the  theoretical 
power  required  to  raise  water  from  deep  wells,  or  to  raise 
water  a  given  height.  In  using  it  an  allowance  must  be 

26 


402 


WATER  SUPPLIES 


made  for  friction  in  the  gearing  and  pipes,  for  it  should 
be  remembered  that  the  fluid  friction  of  water  traversing 
a  pipe  varies  directly  as  the  length  of  the  pipe  and  as  the 
square  of  the  velocity.  Doubling  the  length  of  a  pipe 
therefore  will  double  the  friction,  whereas,  diminishing 
the  internal  area  by  half  will  increase  it  four-fold :  — 


Maximum  Height  to  which  Water  can  be  raised. 

Quantity  of 

Water 
raised  per 
Hour. 

By  one  Man 
turning  a 
Crank. 

By  one 
Donkey 
working 
a  Gin. 

By  one 
Horse 
working  a 
Gin. 

By  one 

Horse-power 
Engine. 

Gallons. 

Feet. 

Feet. 

Feet. 

Feet. 

225 

80 

160 

560 

880 

360 

50 

100 

350 

550 

520 

35 

70 

245 

385 

700 

25 

50 

175 

275 

900 

20 

40 

140 

220 

It  is  assumed  that  a  good  class  double  or  treble-barrel  pump 
is  used. 

Wind  as  a  motive  power  for  driving  pumps  is  again 
receiving  considerable  attention  in  consequence  of  the  intro- 
duction of  improvements  rendering  the  wind  engine  more 
reliable,  more  uniform  in  action,  less  liable  to  damage  by 
storms,  etc.  For  pumping  water  to  supply  farms,  groups 
of  cottages,  and  mansions,  the  wind  can  often  be  utilised. 
Beyond  the  first  cost  of  the  engine  there  is  practically  no 
expense,  and  in  the  most  modern  mills  self-regulating 
gearing  reduces  the  personal  attention  required  to  a 
minimum.  Naturally  they  are  most  efficient  in  exposed 
situations,  but  they  can  be  utilised  anywhere  if  placed  at 
such  an  elevation  as  to  receive  the  full  force  of  any  wind 
which  blows.  The  mill  will  work  from  30  to  35  per  cent,  of 
the  possible  time,  but  to  provide  for  the  periods  of  calm 
it  is  necessary  to  have  the  mill  amply  large  and  a  storage 
reservoir  capable  of  holding  from  four  to  seven  days'  supply 


PUMPS  AND  PUMPING  MACHINERY 


403 


of  water.  Unless  these  precautions  are  taken  in  the  first 
instance,  occasional  failures  in  the  supply  are  certain  to 
occur,  necessitating  the  provision  of  a  steam  or  other 
engine,  or  gearing  for  animal  power,  to  work  the  pumps 
during  the  intervals  of  calm. 

The  wind  engine  may  be  fitted  with  a  crank,  to  which 
the  piston  rod  of  the  pump  is  directly  attached.  This 
form,  however,  is  only  adapted  for  raising  very  limited 
supplies  of  water ;  for  larger  quantities,  or  where  the  water 
has  to  be  drawn  from  a  considerable  depth  or  forced  to  a 
height,  it  is  better  to  connect  with  gearing  from  which  a 
double  or  treble-barrel  pump  can  be  worked.  Mills  with 
annular  sails  are  now  almost  exclusively  employed  for 
pumping  purposes,  and  the  sails  may  be  either  "  solid " 
or  "  sectional."  In  the  "  solid  "  form  each  sail  is  pivoted  at 
both  ends,  and  coupled  together  with  rods,  and  so  adjusted 
as  to  develop  the  maximum  of  power  when  working. 
An  automatic  regulator  causes  the  sails  to  furl  when  the 
wind  pressure  becomes  too  high,  and  so  ensures  the  safety 
of  the  mill.  The  head  also  revolves,  and  is  kept  facing  the 
wind  either  by  a  large  tail  vane  or  a  tail-steering  wheel. 
By  aid  of  levers  the  engine  can  be  started  or  stopped  and 
its  speed  regulated.  In  the  "  sectional "  wheel  the 
individual  sails  are  not  pivoted  into  any  framework,  but  are 
fixed  at  a  definite  angle  and  connected  together  into  a  series 
of  sections  which  vary  in  number  with  the  size  of  the 
wheel.  Each  section  carries  a  weight  or  counterpoise  so 
hung  that  when  the  wind  is  very  high  the  wheel  opens 
and  assumes  a  tubular  form,  allowing  the  wind  to  pass 
through.  When  the  wind  falls  the  sails  resume  their 
normal  position  and  the  mill  is  again  in  action.  It  is 
claimed  that  this  form  is  safer  in  a  storm,  is  more  easily 
regulated  to  work  at  a  uniform  speed,  and  is  more  sensitive 
to  light  breezes.  Either  form  can  be  fitted  with  an 
automatic  appliance  for  keeping  the  water  in  the  supply 
tank  or  ^reservoir  at  a  ,gUJinite  height.  Where  water  has 


4o4  WATER  SUPPLIES 

only  to  be  raised  a  few  feet,  the  wind  engine  may  work  an 
Archimedean  screw,  or  a  dash  wheel,  or  a  "  Noria  "  pump 
(an  endless  chain  carrying  a  series  of  small  buckets),  instead 
of  the  ordinary  force  or  lift  pump.  Such  contrivances, 
however,  are  only  adapted  for  raising  water  for  irrigation 
and  similar  purposes. 

The  amount  of  power  developed  by  these  engines  varies 
with  the  diameter  of  the  wheel,  its  construction,  and  the 
velocity  of  the  wind.  If  built  on  correct  principles  the 
wind  will  produce  the  same  effect  upon  the  wheel  of  one 
maker  as  upon  another,  but  a  difference  may  arise  from 
loss  of  power  by  friction,  leverage,  gearage,  etc.  Where  the 
mill  has  to  be  fixed  at  some  distance  from  the  pumps,  the 
transmission  of  the  power  causes  further  loss.  Whilst  some 
makers  claim  that,  with  a  wind  of  18  miles  an  hour,  their 
machines,  with  wheel  of  13  feet  diameter,  have  2  horse- 
power, other  makers,  more  modest,  claim  only  to  give  1 
horse-power  with  such  a  wheel.  Roughly  stated,  the  power 
of  a  wind  engine  varies-  directly  as  the  square  of  the 
diameter  of  the  wheel,  that  is,  a  20-foot  wheel  will  do  twice 
the  work  of  one  15  feet,  and  four  times  that  of  one  10  feet 
in  diameter.  As  an  approximate  guide  to  the  amount  of 
water  which  a  wind  engine  of  modern  construction  will 
raise,  the  following  estimates  may  be  useful.  The  water 
raised  is  given  in  gallons  per  hour,  and  the  wind  is  assumed 
to  be  blowing  at  a  rate  of  from  14  to  18  miles  an  hour. 
It  must  also  be  remembered  that  the  average  day's  work 
corresponds  to  about  eight  hours. 


PUMPS  AND  PUMPING  MACHINERY 


405 


Diameter 
of  Sail. 

Quantity  raised 
per  Hour. 

Height 
raised. 

Daily  Supply. 

Feet. 

Gallons. 

Feet. 

Gallons. 

Maker  A. 

10 

200 

100 

1,600 

j  j 

12 

250 

150 

2,000 

Maker  B. 

10 

250 

100 

2,000 

9  ) 

12 

250 

150 

2,000 

12 

400 

100 

3,200 

Maker  C. 

10 

240 

50 

1,920 

12 

240 

100 

1,920 

Maker  D. 

10 

210  to  300 

100 

1,680  to  2,400 

ii 

10 

300  to  450 

50  to  60 

2,400  to  3,600 

12 

300  to  500 

100 

2,400  to  4,000 

it 

30 

7,000? 

150 

Expressed  in  terms  of  h.-p.,  a  10-foot  mill  will  give  £-1  h.-p.,  a  12- 
foot  mill  1-1£  h.-p.,  a  14-foot  mill  l£-2  h.-p.,  a  16-foot  mill  2-2£  h.-p., 
an  18-foot  mill  2£-3  h.-p.,  and  a  20-foot  mill  3-4  h.-p. 

Estimates  by  different  makers  for  pumping  engines  of 
various  kinds  can  readily  be  obtained,  but  in  considering 
those  for  wind  engines  it  must  be  remembered  that  the 
storage  capacity  required  is  much  larger  than  with  any 
other  form  of  engine,  and  therefore  increases  the  initial 
expense.  Where  a  larger  supply  than  20,000  gallons  per 
day  is  required,  a  steam  or  gas  engine  is  probably  in  all 
cases  preferable,  but  for  raising  smaller  supplies  the 
possibility  of  using  the  wind  as  the  motive  power  is 
always  worthy  of  serious  consideration. 

Water  Power.  —  Running  water,  when  available  in 
sufficient  quantity,  is  one  of  the  cheapest  and  most  manage- 
able sources  of  power  for  pumping  purposes.  It  may  be 
utilised  by  means  of  water-wheels,  turbines,  or  rams,  the 
choice  often  depending  on  the  fall  which  can  be  utilised, 
the  amount  of  water  to  be  supplied,  and  the  height  to 
which  it  has  to  be  raised;  but  in  some  cases,  where  any 
form  is  applicable,  the  selection  will  be  influenced  by  minor 
considerations.  Whilst  water-wheels  and  turbines  are 
occasionally  used  for  pumping  large  quantities  of  water, 


4o6 


WATER  SUPPLIES 


rams  are  rarely  used  when  more  than  10,000  gallons  a  day 
have  to  be  raised.  As  the  hydraulic  ram,  where  it  can  be 
utilised,  is  probably  the  simplest  and  cheapest,  it  may  be 
considered  first. 

Its    construction    will    be    rendered    intelligible    by    the 
following  section  and  description  (Fig.  22)  :  — 


FIG.  22. — A  is  the  feed  pipe  communicating  with  the  reservoir  supplying 
the  water,  B  the  escape  valve,  C  the  valve  leading  to  the  air-vessel,  D,  E  is  the 
rising  main.  When  water  is  admitted  to  A,  it  at  first  escapes  through  the 
valve  B,  which  opens  downwards,  but  as  the  maximum  velocity  is  reached  the 
force  is  sufficient  to  close  the  valve.  The  flow  being  suddenly  stopped,  the 
pressure  rises,  and  lifts  the  valve  C,  which  opens  upwards,  a  certain  amount 
of  water  entering  the  air-vessel  D.  The  pressure  being  relieved  by  the  recoil, 
both  valves  fall.  The  water  again  escapes  at  B,  and  the  action  described  is 
repeated.  The  intermittent  flow  into  C  is  converted  by  the  compressed  air  into 
a  constant  flow  through  the  rising  main  E. 

In  this  ram  it  is  obvious  that  the  water  working  the  ram 
is  the  same  as  that  which  enters  the  rising  main,  and  as  the 
proportion  of  water  /raised  to  that  wasted  is  invariably 
small,  its  utility  is  somewhat  limited.  Recently,  however, 
a  double-acting  ram  has  been  devised,  whereby  an  impure 


PUMPS  AND  PUMPING  MACHINERY  407 

water  by  its  fall  is  caused  to  pump  water  from  a  purer 
source.  As  yet  these  are  not  in  general  use. 

These  self-acting  pumps  work  day  and  night,  and  if  by 
a  good  maker,  and  properly  adapted  for  the  work  they  have 
to  perform,  the  amount  of  attention  and  repair  required 
during  the  year  is  remarkably  little,  as  there  are  no  parts 
requiring  packing  or  lubricating.  With  a  reservoir  holding 
sufficient  to  meet  one  or  two  days'  demand,  repairs,  when 
necessary,  can  be  effected  without  interfering  with  the 
supply.  Where  large  quantities  of  water  are  being  pumped, 
a  duplicate  ram  is  desirable. 

The  smallest  fall  which  can  be  utilised  is  about  18  inches ; 
the  greater  the  fall  the  larger  the  proportion  of  water,  and 
the  greater  the  height  to  which  it  can  be  raised.  Although 
falls  of  40  feet  are  sometimes  used,  the  wear  and  tear 
consequent  upon  the  friction  and  shock  necessitates  the  use 
of  specially-constructed  rams.  Special  rams  are  also  made 
which  will  lift  water  a  height  of  800  feet,  and  the  water  so 
raised  may  be  caused  to  act  upon  a  second  ram  and  raise 
a  portion  of  the  water  to  a  height  of  1,500  feet.  Rams, 
however,  are  rarely  used  to  lift  water  to  more  than  150  to 
200  feet,  as  the  amount  of  water  wasted  compared  to  that 
supplied  increases  with  the  elevation,  but  more  rapidly  than 
the  elevation  on  account  of  the  increased  friction.  A  ram 
of  best  construction  will  raise  water  30  times  the  height  of 
the  fall,  but  it  is  not  safe  to  depend  upon  delivering  it 
at  more  than  25  times  the  height.  Where  the  water  supply 
is  not  sufficient  to  work  a  ram  continuously,  it  may  often 
be  dammed  up  and  discharged  at  intervals  by  a  syphon 
arrangement,  the  ram  then  working  intermittently. 

Theoretically,  disregarding  friction,  the  product  of  the 
amount  of  water  falling  in  a  given  time  into  the  fall  should 
be  equal  to  the  product  of  the  amount  raised  into  the 
height.  Thus  100  gallons  falling  10  feet  would  raise  10 
gallons  100  feet,  20  gallons  50  feet,  or  100  gallons  10  feet, 
etc.  Friction  and  imperfections  in  construction,  however, 


4o8 


WATER  SUPPLIES 


render  such  a  degree  of  efficiency  unattainable ;  but  some 
of  the  best  of  most  modern  rams  have  reached  over  80  per 
cent,  of  efficiency,  even  with  a  rising  main  of  considerable 
length  and  when  the  water  was  being  lifted  over  100  feet. 
The  smaller  the  fraction  expressed  by  the  ratio  of  the  fall 
to  the  height  raised,  the  less  the  efficiency.  Tables  giving 
the  efficiency  for  different  ratios  have  been  published,  but 
they  are  quite  useless.  Thus  in  a  table  recently  issued 
the  efficiency  of  a  ram  with  a  ratio  of  fall  to  height  of  TL 
is  given  as  37  per  cent.,  whilst  more  than  one  English 
maker  will  guarantee  at  least  50  per  cent.,  and  69  per  cent, 
has  been  attained.  Allowing  for  the  friction  in  a  moderate 
length  of  rising  main,  a  good  ram  properly  fixed  should 
supply  not  less  than  the  following  percentages  of  the 
theoretical  amount :  — 


Fall 

Efficiency  Rtt£tin6d  fov 

Height 
raised. 

Degree  of  Efficiency. 

Blake's  Rains. 

* 

86  per  cent. 

i 

76 

78  per  cent. 

i 

70 

83 

* 

66 

72 

* 

63 

f 

60 

75 

i 

58 

i 

56 

TV 

54 

TV 

52 

69      '"„ 

Example. — It  is  required  to  know  what  amount  of  water 
can  be  raised  to  a  height  of  100  feet,  by  a  ram  working 
with  a  fall  of  10  feet,  the  amount  of  water  available  being 
20,000  gallons  per  day. 

Here  the  ratio  y1^  should  give  an  efficiency  of  at  least 
54  per  cent.  With  perfect  efficiency  the  amount  raised 
would  be  2,000,  since 


2,000  x  100  =  20,000  x  10 


PUMPS  AND  PUMPING  MACHINERY  409 

and  2,000  xT5^=  1,080,  which  is  the  number  of  gallons  per 
day  the  ram  should  be  guaranteed  to  raise  to  the  required 
height. 

The  efficiency  decreases  very  rapidly  when  the  ratio  of 
the  fall  to  the  height  raised  exceeds  T^,  so  that  when  ~  is 
reached  the  proportion  of  water  pumped  to  that  wasted 
becomes  a  very  small  fraction  indeed.  In  such  cases  other 
forms  of  water  motors  are  preferable ;  moreover,  with  a  fall 
of  over  10  feet  the  wear  and  tear  becomes  so  very  consider- 
able that  it  is  not  desirable  to  attempt  to  utilise  much 
greater  falls  with  a  ram.  These  conditions,  therefore, 
limit  the  general  usefulness  of  the  ram  to  situations  where 
the  fall  of  water  available  is  from  1J  to  10  feet,  and  where 
the  supply  has  not  to  be  raised  more  than  250  feet. 

A  turbine  can  often  be  used  where  a  ram  is  inadmissible. 
In  the  ram  the  pump  is  a  part  of  the  machine,  whereas  a 
turbine  is  merely  a  machine  for  utilising  a  fall  of  water  to 
supply  the  power  to  work  a  pump  or  set  of  pumps.  It 
follows,  therefore,  that  a  turbine  worked  by  a  falling 
stream  may  be  used  for  pumping  water  from  any  source, 
as  from  a  deep  well,  and  the  pumps  may  be  placed  at  any 
convenient  distance  from  the  source  of  power,  the  con- 
nection being  made  by  suitable  gearing.  Any  fall  from 
1  to  1,000  feet  can  be  taken  advantage  of,  and  there  is 
practically  no  limit  to  the  depth  from  which  the  supply 
can  be  raised,  or  to  the  height  to  which  it  can  be  propelled. 
Moreover,  they  can  be  so  constructed  as  to  work  with 
fluctuating  falls  and  a  constant  efficiency  of  75  per  cent, 
attained.  In  experimental  trials  the  best  turbines  have 
yielded  87  per  cent,  of  the  actual  power  of  the  water,  but 
even  with  the  best  makers  it  is  not  safe  to  rely  upon  more 
than  75  per  cent. 

The  numerous  varieties  of  turbines  may  be  divided  into 
two  classes.  In  the  first  or  "  pressure  "  turbine  the  falling 
water  is  conducted  through  one  or  more  pipes  and  allowed 
to  impinge  upon  the  vanes  of  a  wheel,  which  revolves  upon 


4io  WATER  SUPPLIES 

a  pivot  and  is  included  in  a  metal  case.  The  impact  of 
the  water  causes  the  wheel  to  revolve  with  a  velocity 
depending  chiefly  upon  the  fall.  After  expending  its 
energy,  the  water  escapes  around  the  centre  of  the  case. 
The  turbine  may  be  fixed  horizontally  or  vertically,  and 
the  vanes  may  be  fixed  or  movable,  the  latter  only  being- 
necessary  where  the  power  required  or  the  water  available 
is  variable.  In  the  second  class  of  turbines  or  "  impulse  " 
turbines,  the  falling  water  (conducted  by  suitable  guides) 
impinges  against  a  series  of  "  buckets/'  arranged  around  the 
periphery  of  the  wheel.  This  turbine,  therefore,  need  not 
be  acted  upon  by  the  water  all  round,  neither  need  the 
wheel  be  submerged.  It  must  always  be  fixed  at  the 
bottom  of  the  fall,  whereas  the  "  pressure  "  turbine  may 
be  placed  as  much  as  20  feet  above,  the  water  escaping  from 
the  centre  passing  down  a  suction  pipe  and  so  contributing 
to  the  available  power.  The  first  form  is  most  generally 
applicable  for  low  and  medium  falls,  and  the  latter  for 
high  falls.  When  the  supply  of  water  is  abundant  and  a 
high  degree  of  efficiency  is  not  necessary,  cheap  forms  of 
the  turbine  may  be  employed ;  but  where  it  is  required 
to  fully  utilise  the  power  a  machine  should  be  obtained, 
the  high  efficiency  of  which  is  guaranteed.  As  large 
turbines  are  more  efficient  than  small  ones,  it  is  often 
advisable  to  store  the  water  during  the  night  and  give  the 
whole  out  during  the  day  to  a  large  turbine,  rather  than 
work  a  smaller  machine  with  the  constant  flow. 

On  the  Continent  turbines  are  much  more  used  than  in 
this  country,  the  largest  installation  probably  being  at 
St.  Maur,  where  four  sets  of  turbines,  each  with  a  diameter 
of  forty  feet,  raise  over  8,000,000'  gallons  of  water  per  day  to 
an  elevation  of  250  feet  for  the  supply  of  the  city  of  Paris. 
The  fall  of  water  utilised  is  only  3  feet.  The  turbines  are 
fixed  with  the  axes  horizontal,  and  are  of  the  "  impulse  " 
class.  The  turbines  pumping  water  for  the  city  of  Geneva 


PUMPS  AND  PUMPING  MACHINERY 


411 


4i2  WATER  SUPPLIES 

are  of  the  same  description,  but  work  with  a  fall  of  165 
feet. 

Probably  the  greatest  height  to  which  water  is  raised  by 
any  machine  is  by  the  turbines  pumping  water  to  supply 
the  town  of  La  Chaux  de  Fonds  (population  30,000).  These 
turbines,  made  by  Mons.  Escher  of  Zurich,  work  with  a 
fall  of  about  100  feet  of  water,  derived  from  the  Gorges  de 
TAreuse,  and  throw  that  supplying  the  town  to  a  height 
of  over  1,600  feet. 

As  an  example  of  a  village  supply  the  works  recently 
executed  at  West  Lulworth  (Dorset)  may  be  cited.  The 
water  from  a  spring  on  the  hillside  is  piped  to  a  tank 
placed  on  a  tower  immediately  over  the  turbine.  The 
vortex  (pressure)  horizontal  turbine  is  fixed  in  a  pit  20  feet 
below  the  level  of  the  water  in  the  tank.  The  water  falls 
to  the  turbine  by  means  of  a  vertical  pipe,  the  waste  water 
being  conveyed  away  from  the  bottom  by  a  12-inch  drain 
and  discharged  into  the  sea.  From  the  turbine,  which  runs 
about  600  revolutions  a  minute,  the  power  is  communicated 
by  a  10-inch  pulley  to  a  larger  pulley  on  the  overhead 
shafting,  and  thence  the  power  is  transferred  to  a  set  of 
three-throw  plunger  pumps.  The  machine  is  estimated  to 
be  of  5  h.p.,  and  will  lift  continuously  1,200  gallons  per  hour 
into  the  service  reservoir,  which  is  on  the  hillside,  300  feet 
above  the  source  of  the  water.  The  reservoir  has  a  capacity 
of  60,000  gallons,  and  as  the  population  to  be  supplied  is 
only  about  400,  it  is  obvious  that  the  reserve  is  ample  to 
admit  of  the  pumping  being  intermittent,  and  to  give  time 
for  repairs,  etc.,  to  the  turbine  when  such  are  needed. 

The  efficiency  of  turbines  decreases  with  the  size;  hence 
for  small  supplies  (of  from  1,000  to  4,000  gallons  per  24 
hours)  a  small  water-wheel,  which  can  be  used  without 
gearing,  is  often  more  economical,  both  in  first  cost  and  in 
amount  of  water  used.  Water-wheels  are  too  well  known 
to  need  any  description.  Recently,  however,  the  substitu- 
tion of  light  iron  wheels  for  the  cumbersome  wooden  ones 


PUMPS  AND  PUMPING  MACHINERY 


previously  used  has  greatly  increased  the  utility  of  this 
machine.  An  "  overshot "  water-wheel  receives  the  water 
near  the  top  and  has  a  higher  degree  of  efficiency  than 
either  the  "  high  breast/'  which  receives  the  water  above 
the  centre,  or  the  undershot  wheel,  which  receives  the 
water  below  the  centre.  Where  sufficient  fall  is  available, 
therefore,  the  overshot  wheel  should  always  be  selected. 
A  fall  of  1  foot  may  be  utilised  for  driving  an  undershot 
wheel,  but  not  less  than  3  feet  is  required  for  the  overshot. 
They  are  quite  as  reliable  as  rams,  and  as  the  wheels 
revolve  at  a  slow  speed  the  shaft  can  be  directly  connected 
with  the  piston  rods  of  the  pumps.  Where  the  water 
available  for  working  the  wheel  is  variable,  an  adjustable 
disc  crank  can  and  should  be  provided,  so  as  to  enable 
the  stroke  of  the  pump  to  be  correspondingly  varied.  The 
following  table  gives  approximately  the  amount  of  water 
which  can  be  raised  per  day  to  a  height  of  100  feet,  with 
wheels  of  different  diameter  and  with  different  supplies  of 
water :  — 


Diameter  of 
Wheel. 

Water  Supply 
per  Minute. 

Quantity  raised  100  Feet 
in  24  Hours. 

4  feet 

60  galls. 

1,000  galls. 

4 

100 

1,850 

4 

500 

9,250 

5 

50 

1,000 

5 

100 

2,000 

5 

250 

5,000 

6 

100 

2,750 

6 

500 

13,750 

These  figures  refer  to  an  "  overshot "  wheel.  A  "  high- 
breast  "  wheel  would  raise  about  5  per  cent,  less,  and  an 
"  undershot "  about  15  per  cent,  less,  assuming  the  fall 
utilised  to  be  the  same.  As  these  wheels  run  night  and 
day,  rarely  require  any  attention,  are  very  inexpensive 
both  to  purchase  and  fix,  and  can  be  worked  by  impure 


4i4  WATER  SUPPLIES 

water,  whilst  raising  a  pure  water  from  a  well,  spring,  or 
other  source,  it  is  obvious  that  under  many  circumstances 
they  are  preferable  to  a  ram,  whilst  under  others  they  can 
be  used  when  the  ordinary  ram  is  inadmissible. 

Fuel  Engines. — Where  neither  wind  nor  water  are  avail- 
able an  engine,  deriving  its  energy  from  the  combustion  of 
fuel  (coal,  wood,  charcoal,  petroleum,  or  gas),  must  be 
employed.  Such  engines  differ  from  those  previously 
described  in  being  a  constant  expense  for  fuel  and 
attention ;  but  the  great  improvements  which  have  been 
effected  in  recent  years,  especially  in  the  construction  of 
small  motors^  has  probably  reduced  this  expenditure  to  a 
minimum.  The  simplest  machines  are  those  which  dispense 
with  the  use  of  steam.  These  are  the  hot-air,  gas,  and  oil 
engines.  The  competition  between  the  makers  of  these 
various  types  of  motors,  not  only  amongst  themselves,  but 
with  the  makers  of  steam  engines,  has  resulted  in  all  being 
brought  to  such  perfection  that  it  is  often  a  difficult  matter 
to  decide  which  form  is  the  most  desirable.  The  hot-air 
engine  is  very  compact  and  economical,  requiring  but  little 
fuel  and  skilled  attention,  but  it  is  only  adapted  for  small 
works,  where  the  h.p.  required  is  from  J  to  1.  Its  only 
competitor  under  such  conditions  is  the  gas  engine,  and  as 
this  is  quite  as  economical  in  cost  of  fuel  where  gas  is 
reasonably  cheap,  and  requires  even  less  attention,  it  would 
probably  be  selected  where  gas  is  available.  The  gas  engine 
is  rapidly  supplanting  the  steam  engine  in  all  but  the 
largest  pumping  stations,  since  they  are  not  only  more 
compact  than  steam  engines,  but,  with  gas  at  a  reasonable 
price,  more  economical,  when  the  great  saving  in  repairs  and 
in  attendance  is  taken  into  consideration.  When  once 
started  they  will  run  for  hours  without  any  attention,  and 
there  is  no  risk  of  explosion  from  neglect.  "  Oil  "  engines 
are  of  more  recent  introduction  and,  owing  to  the  cheapness 
of  petroleum,  are  claimed  to  be  more  .economical  than  gas 
engines  should  the  cost  of  gas  be  over  2s.  6d.  per  1,000  feet. 


PUMPS  AND  PUMPING  MACHINERY  415 

It  is  also  asserted  that  the  cost  of  the  oil  used  does  not  ex- 
ceed that  of  the  corresponding  amount  of  coal  required  in 
driving  a  steam  engine,  when  such  coal  can  be  obtained  at 
10s.  a  ton.  Where  coal  is  more  expensive  there  is  a  saving  in 
the  cost  of  fuel,  but  in  all  cases  there  is  saved  the  wages  of 
stoker  and  driver  and  the  cost  of  water.  As  the  oil  used 
has  a  high  flashing  point  there  is  no  risk  of  explosion,  and 
the  danger  from  fire  is  reduced  to  a  minimum.  In  the  best 
machines  the  vapouriser  is  heated  by  a  small  lamp,  taking 
about  5  to  15  minutes.  As  soon  as  the  temperature  is 
sufficiently  high  the  engine  will  start  when  the  fly-wheel  is 
turned.  The  vapouriser  is  afterwards  maintained  at  a 
sufficiently  high  temperature  by  the  continuous  explosions. 
When  once  started  the  only  attention  required  is  periodical 
lubrication  and  the  occasional  replenishing  of  the  oil  reser- 
voir. In  fact,  after  being  set  in  motion  it  requires  no  more 
attention  than  the  gas  engine.  .  i 

These  engines  are  now  made  to  work  up  to  40  h.p.,  and 
where  gas  is  not  obtainable  there  is  no  doubt  that  they  will 
be  extensively  employed. 

In  order  to  enable  gas  engines  to  compete  with  oil  engines 
where  there  is  no  public  gas  supply,  plants  are  now  made 
for  converting  petroleum  oils,  fat  and  grease  of  all  kinds, 
into  gas,  and  it  is  claimed  that  the  gas  so  produced  is 
cheaper  than  coal-gas.  Water-gas  may  also  be  manu- 
factured and  used  for  this  purpose.  As  the  "  oil  "  engines 
convert  the  petroleum  into  gas  in  the  vapouriser  drop  by 
drop  as  it  is  required,  there  does  not  seem  to  be  any 
advantage  in  or  any  necessity  for  constructing  a  gasworks, 
unless  gas  is  required  for  other  purposes  besides  that  of 
supplying  the  motive  power  to  the  engine. 

Steam  engines,  except  for  large  waterworks,  are  not 
likely  to  be  seriously  considered  as  a  source  of  power  on 
account  of  the  comparatively  large  expense  entailed  in 
labour.  For  large  works,  however,  they  continue  to  be  the 
only  practical  and  efficient  motQ-rs.  In  such  gases,  also,  tha 


416  WATER  SUPPLIES 

compound  condensing  engine  will  be  used.  For  engines 
under  10  h.p.  the  saving  effected  by  the  use  of  a  condensing 
arrangement  will  not  compensate  for  the  additional  cost  of 
the  engine.  The  pumps  may  be  driven  by  a  steam  engine 
either  .directly  or  through  the  intervention  of  a  crankshaft 
and  fly-wheel.  In  the  former  case  the  pistons  of  the 
cylinder  and  of  the  pump  are  continuous,  in  the  latter  the 
piston  of  the  cylinder  acts  upon  the  fly-wheel  and  the  pump 
piston  is  attached  to  a  crank.  The  crankshaft  engine 
requires  more  space  and  stronger  foundations  than  the 
"  direct "  form,  and  as  the  latter  are  now  being  made 
"  compounding  "  and  with  high  duty  gear,  and  are  more 
compact,  they  will  be  generally  preferred. 

In  calculating  the  horse  power  required  for  pumping  a 
supply  of  water,  the  chief  factors  are  :  (a)  the  quantity  of 
water  to  be  raised,  and  (b)  the  height  to  which  it  has  to 
be  lifted  or  forced.  Besides  this,  an  approximate  estimate 
must  be  made  of  the  power  which  will  be  required  to  over- 
come the  friction  due  to  gearing,  and  the  passage  of  the 
water  through  the  pipes.  The  loss  from  friction  in  the 
pipes  will  depend  upon  the  nature  of  the  surface  of  the 
pipe,  degree  of  smoothness  or  roughness,  but  more  upon  the 
diameter  and  velocity  with  which  the  water  is  traversing 
it.  It  is  of  the  highest  importance  to  have  all  the  mains 
of  sufficient  diameter,  since  the  friction  increases  with  the 
square  of  the  velocity.  Thus  the  friction  in  a  pipe  dis- 
charging a  certain  number  of  gallons  per  minute  will  be 
increased  fourfold  if  the  discharge  be  only  doubled.  The 
friction  also  increases  directly  as  the  length  of  the  main. 
The  main  should  always  be  of  such  diameter  that  the 
velocity  shall  not  exceed  2  feet  per  second  (Rawlinson). 
With  this  velocity  the  discharge  from  pipes  of  different 
diameters  is  given  in  the  following  table.  It  will  be 
observed  that  the  volume  for  any  pipe  can  be  calculated  by 
multiplying  the  square  of  the  diameter  in.  inches  by  the 
volume  discharged  from  a  1-inch  pipe:  — 


P UMPS  AND  P UMPING  MA CHINER Y 


Diameter  of  Pipe. 

Volume  of  Water  discharged 
per  Minute  with  a  Velocity 
of  2  Feet  per  Second. 

1    inch 

4-1  gallons 

1£  inches 

9-2 

2 

16-4 

3 

37-0 

4 

65-0 

6 

148-0 

8 

260-0 

10 

410-0 

12 

590-0 

With  pipes  of  such  ample  diameter  the  loss  from  friction 
is  very  small  and  practically  negligible. 

An  engine  of  one  *  actual  horse  power  will  raise  3,300 
gallons  1  foot  high  per  minute,  and  any  smaller  quantity  to 
a  proportionately  greater  height.  From  the  following 
simple  formula  the  h.p.  required  to  pump  any  given 
quantity  of  water  can  easily  be  calculated  :  — 

G  x  H    w  T> 
"3,300  =ILP" 

where  G  =  the  number  of  gallons  to  be  pumped  per  minute 
and  H  =  the  height  to  which  it  has  to  be  raised. 

The  allowance  for  overcoming  the  friction  of  the  bucket 
or  plunger  in  the  pumps,  and  of  the  movement  of  the  water 
in  the  pipes,  and  for  raising  the  piston  rods  (when  pumping 
from  a  deep  well),  cannot  be  exactly  calculated.  It  is 
better  to  err  on  the  safe  side  and  allow  80  per  cent,  for 
small  engines  and  40  per  cent,  for  larger  powers. 

In  all  waterworks  it  is  necessary  to  provide  more  pumping 
engines  than  are  actually  at  any  one  time  required,  in 

*  By  actual  horse  power  is  meant  the  actual  power  of  an  engine  given 
from  the  shaft  or  fly-wheel.  The  term  "  indicated  "  horse  power,  which 
is  frequently  used,  is  the  power  given  off  in  the  cylinder,  and  is,  of 
course,  higher  than  the  actual  or  available  power.  Another  term  often 
employed  by  makers  of  engines  is  "nominal"  horse  power.  It  is  a 
variable  quantity,  and  so  misleading  that  it  should  be  abandoned. 

27 


418  WATER  SUPPLIES 

order  to  provide  for  such  contingencies  as  a  break-down  or 
laying-off  for  repairs.  "  In  the  case  of  small  waterworks  it 
is  common  to  have  double  the  quantity  of  power  needed, 
in  the  form  of  two  pumping  engines,  either  of  which  is 
capable  of  doing  all  the  work.  The  reason  for  this  is  that 
the  first  cost  would  probably  be  rather  increased  than 
otherwise,  by  subdividing  the  work  more  when  the  engines 
are  very  small,  even  although  the  total  horse  power  might 
be  less.  Thus  suppose  the  total  horse  power  needed  were 
six  i.h.p.*  Two  engines  of  six  i.h.p.  each  would  probably 
not  cost  more  than  three  of  three  i.h.p.  each ;  moreover,  in 
work,  the  efficiency  of  the  one  pumping  engine  of  six  i.h.p. 
would  be  greater  than  that  of  the  two  of  three  i.h.p.  each. 
Of  course  there  is  no  hard-and-fast  line  between  small  and 
large  works,  but  it  may  be  very  roughly  said  that  it  is  not 
advisable  to  subdivide  the  pumping  power  into  more  than 
two  engines  if,  by  so  doing,  separate  engines  of  less  than  ten 
i.h.p.  each  have  to  be  provided.  In  the  case  of  large  water- 
works the  stand-by  power  need  only  equal  one-third,  one- 
fourth,  or,  in  the  case  of  very  large  works,  perhaps  one-fifth 
of  the  whole,  there  being,  in  such  cases,  three,  four,  or  five 
pumping  engines  "  (Burton,  The  Water  Supply  of  Towns). 
Where  engines  are  employed  requiring  the  use  of  fuel  and 
attendance,  it  is  desirable  to  have  the  machinery  of  such 
power  that  the  whole  of  the  water  required  during  twenty- 
four  hours  can  be  pumped  in  a  much  shorter  time.  For 
mansions,  farms,  etc.,  the  engines  may  be  sufficiently 
powerful  to  raise  in  eight  or  twelve  hours  as  much  water 
as  will  serve  for  three  or  four  days,  thus  necessitating 
pumping  only  twice  a  week.  For  village  water  supplies 
pumping  for  from  four  to  six  hours  daily  should  suffice. 
For  towns  up  to  20,000  inhabitants  the  pumps  should  raise 
in  ten  hours  the  whole  day's  supply.  For  larger  towns  the 
pumping  would  probably  be  continuous.  Naturally  the  h.p. 
required  will  have  to  be  regulated  by  the  quantity  of  water 
which  has  to  be  raised  in  the  given  time. 
*  Indicated  horse  power. 


CHAPTER  XXII. 

THE  STORAGE  OF  WATER. 

WHERE  a  water  supply  is  derived  from  the  rainfall  upon 
any  catchment  area,  it  is  obvious  that,  whether  it  is  to  meet 
the  demand  of  a  single  house,  or  of  a  whole  town,  sufficient 
storage  must  be  provided  to  tide  over  the  longest  periods 
of  drought  ever  likely  to  occur,  and  to  equalise  the  supply 
during  a  succession  of  dry  seasons.  The  various  ways  in 
which  the  amount  of  storage  necessary  is  calculated,  and 
the  opinions  of  various  engineers  and  hydrologists  thereon, 
have  already  been  recorded  in  Chapter  XVII.,  where  the' 
amount  of  water  available  from  different  sources  has  been 
considered.  The  reservoirs  used  for  the  above  purposes  are 
called  "  impounding  "  reservoirs,  and  when  of  large  size 
they  are  usually  situated  in  a  valley,  or  at  the  junction  of 
two  valleys,  where,  by  excavation  and  the  construction  of  a 
dam,  a  sufficient  quantity  of  water  can  be  collected. 

The  ground  must  be  first  surveyed  to>  ascertain  the 
character  of  the  impervious  stratum  and  its  distance  from 
the  ground  surface.  If  of  rock,  its  freedom  from  fissures 
(common  in  certain  formations),  through  which  the  water 
could  escape,  must,  if  possible,  be  determined.  The 
presence  of  an  undiscovered  fissure  may  result  in  the 
reservoir,  after  construction,  having  tc*  be  abandoned,  or  in 
the  expenditure  of  large  sums  of  money  in  detecting  and 
attempting  to  remedy  the  defect.  The  dam  may  be  of 
masonry  or  of  earthwork,  but  the  former  is  only  applicable 
where  there  is  a  rocky  foundation.  The  latter  can  be 

(419) 


420  WATER  SUPPLIES 

constructed  on  rock,  clay,  or  other  impervious  strata,  and 
is  less  costly  than  masonry.  If,  however,  the  water  is  once 
able  to  penetrate  it,  the  channel  will  continuously  increase 
in  size  and  the  dam  will  be  .destroyed,  whereas  defects  in 
masonry  dams  have  not  this  tendency  to  continuous  increase 
and  admit  of  being  more  easily  discovered  and  remedied. 
All  vegetable  matter  should  be  removed  from  the  sides  and 
bottom  of  new  reservoirs,  otherwise  these,  by  their  decom- 
position, will  give  up  organic  matter  to  the  water, 
favourable  to  the  growth  of  low  forms  of  life.  To  draw 
off  the  water  a  valve  tower  is  provided,  which  admits 
of  valves  being  opened  at  various  depths,  so  as  to  avoid 
drawing  either  from  too  near  the  surface  or  too  near 
the  bottom.  A  meter  house  may  be  required,  in  which 
to  fix  the  apparatus  for  recording  the  amount  of  water 
which  is  passing  into>  thi©  mains,  or  the  amount  of  com- 
pensation water  being  supplied,  or  both,  and  a  by-pass  to 
allow  of  flood  water  being  diverted  from  the  reservoir,  and 
to  prevent  the  water  rising  above  a  certain  level. 

According  to  Rawlinson,  the  outer  portion  of  the  embank- 
ment must  be  effectively  drained,  and  if  there  are  springs 
of  water  in  the  puddle  trench  (as  there  usually  are),  these 
must  be  collected  and  brought  away.  No  form  of  culvert 
or  other  works  for  drawing  off  water  should  be  constructed 
within  or  beneath  or  through  the  deepest  made  portion  of 
the  bank,  but  the  outlet  tunnel,  valve  chamber,  and  works 
connected  with  the  drawing  off  of  the  water  must  be  in  the 
solid  ground,  on  the  side  of  the  valley.  At  the  centre  of 
the  bank  the  valve  chamber  should  be  formed.  All  pipes 
and  valves  should  be  so  placed  as  to  be  easily  reached  for 
repairs  or  renewals,  and  it  should  be  so  arranged  that  no 
valve  in  the  tier  of  valves  in  the  valve  well  need  be  worked 
under  a  greater  head  than  10  or  15  feet. 

Referring  to  storage  reservoirs,  Whitaker,  in  his  anni- 
versary address  to  the  Geological  Society,"*  says  :  — 

*  Quart.  Journal  Geol.  Soc.,  1899. 


THE  STORAGE  OF  WATER  421 

"  In  the  selection  of  sites  for  reservoirs  more  particular 
points  have  to  be  considered,  especially  where  high  dams  are 
to  be  constructed.  In  such  work  it  is  well,  as  far  as 
possible,  to  avoid  places  where  there  is  any  great  disturb- 
ance, whether  by  faulting  or  otherwise. 

"  Masses  of  Drift,  too,  are  sometimes  troublesome,  and 
it  may  be  needful  to  study  the  composition  of  these  and 
their  relation  to  the  rocks  beneath:  irregular  mixtures 
of  permeable  and  impermeable  yielding  material  are  likely 
to  cause  trouble,  and  the  uneven  way  in  which  Drift  so 
often  occurs  leads  to  uncertainty  as  to  its  thickness.  On 
the  whole,  therefore,  those  parts  of  a  valley  with  much 
Drift  are  to  be  avoided,  although  sometimes  a  bank  or 
sheet  of  solid  Boulder  Clay  may  be  useful.  Professor  Boyd 
Dawkins  has  lately  drawn  attention  to  this  matter,  in  a 
lecture  delivered  to  the  Institution  of  Civil  Engineers,* 
noticing  a  case,  at  the  Ogden  Reservoir  (for  Sheffield),  where 
Boulder  Clay  made  a  more  or  less  water-tight  bottom,  and 
another  (Yarrow  Reservoir,  Rivington)  where  Drift  (sand, 
gravel,  Boulder  Oay,  and  loam)  filled  up  a  deep  pre-Glacial 
valley  and  caused  much  difficulty. 

"  Tracts  in  which  there  are  large  landslips  are  clearly 
dangerous;  for,  with  rocks  as  with  men,  where  a  slip  has 
occurred,  there  another  is  likely  to  happen  some  day,  as 
witness  the  Saiidgate  landslip  of  1893,  which  was  within 
the  area  of  an  older  slip.  Moreover,  the  process  of  cutting 
into  a  slipped  mass  of  rock  and  earth  is  likely  to  start  fresh 
slips,  and  to  endanger  the  stability  of  the  work.  An 
instance  of  this  may  be  given  from  the  Manchester  Water- 
works in  the  Valley  of  the  Etherow,  several  miles  east  of 
the  city,  made  many  years  ago,  when  the  characteristics  of 
old  landslipped  tracts  were  not  so  well  recognised  as  now. 
The  lower  part  of  the  deep  valley  along  which  the  set  of 
reservoirs  has  been  made  is  in  Millstone  Grit;  but,  above 

*  Proc.  Inst.  Civ.  Eng.,  vol.  cxxxiv.  (1898),  p.  270? 


422  WATER  SUPPLIES 

this,  the  part  in  which  most  of  them  are  placed  has  been 
cut  through  the  Millstone  Grit  to  the  Yoredale  Beds, 
especially  on  the  southern  side.  The  Yoredale  Beds  being 
largely  composed  of  shale,  the  conditions  are  favourable  to 
springs  and  slips,  and,  as  noted  on  the  Geological  Survey 
map  (Sheet  88,  S.E.),  the  greater  part  of  the  southern  side 
of  the  valley  is  a  landslip-area.  The  features  of  this  are 
very  clear,  especially  in  the  neighbourhood  of  the  Woodhead 
Reservoir,  the  highest  of  the  series,  the  dam  of  which 
impinges  on  the  landslip,  by  Crowden  Station.  Under 
these  circumstances,  one  is  not  surprised  to  hear  that  this 
reservoir  was,  for  some  years,  never  filled  to  within  15  or  20 
feet  of  its  height,  because  it  was  thought  unsafe  to  fill  it, 
owing  to  a  landslip  and  to  the  unsoundness  of  the  embank- 
ment, until  a  new  embankment  had  been  made.  I  under- 
stand, indeed,  that  the  dam  is  now  practically  double. 

'  In  the  above  remarks  I  am  not  finding  fault  with  this 
fine  set  of  works,  but  only  showing  how  difficulties,  of  a 
nature  that  a  geologist  would  expect,  interfered  with  the 
plans  of  so  good  an  engineer  as  the  late  Mr.  Bateman.  I  am 
inclined  to  think,  indeed,  that  old  landslips  are  more 
common  than  most  geologists  suppose.  In  my  Geological 
Survey  work  in  Hampshire  I  found  that  the  right,  or 
western,  bank  of  the  Test,  near  Romsey,  was  for  a  long 
distance  a  great  slip,  with  the  usual  irregular  features ;  and 
later  on  the  same  was  found  to  be  the  case  with  the  left,  or 
eastern,  bank  of  the  Itchen  opposite  Southampton.  In 
both  cases  no  beds  in  place  could  be  seen,  except  the  gravel 
at  the  top.  So  far  as  I  know,  these  two  occurrences  had 
never  been  noticed ;  but  many  others  have  been  observed, 
especially  in  the  later  work  of  the  Geological  Survey. 

"  Another  matter  that  may  give  trouble  in  a  reservoir, 
and  has  to  be  guarded  against,  is  the  occurrence  of  per- 
meable beds  through  which  the  water  may  find  a  way  to 
lower  ground,  under  favourable  circumstances.  An 
example  of  this  may  be  given  from  another  set  of  reservoirs 


THE  STORAGE  OF  WATER  423 

of  a  like  kind  to  that  already  noticed,  along  the  valley  of 
the  Loxley  for  the  supply  of  Sheffield.  That  portion  of 
the  valley  in  which  the  reservoirs  are  placed  is  cut  out  of 
the  upper  part  of  the  Millstone  Grit  Series,  which  consists 
of  alternations  of  grits  and  shales.  From  the  slight  easterly 
dip  of  the  beds,  down  the  valley  and  at  a  higher  angle  than 
the  bottom-slope,  the  Middle  Coal  Measures  are  carried 
down  to  the  bottom  by  the  eastern  end  of  the  Damflask 
Reservoir,  and  in  part  the  sides  and  bottom  of  this  reservoir 
consist  of  a  porous  grit,  down  which  water  passed  to  below 
the  dam.  To*  get  over  this  difficulty  a  long  trench  had  to 
be  made  along  the  southern  side  and  filled  with  water-tight 
materials." 

In  cases  also  where  the  water  is  derived  from  springs 
and  streams  of  variable  flow,  the  supply  sometimes  falling 
below  that  of  the  average  demand,  impounding  reservoirs 
are  necessary  to  equalise  the  supply.  The*  size  will  depend 
upon  many  circumstances,  but  will  be  chiefly  influenced  by 
the  length  of  time  during  which  the  yield  is  below  the 
average,  and  by  the  extent  of  the  fluctuations.  Where 
river  water  is  impounded  it  must  also  be  remembered  that 
at  certain  periods,  following  heavy  rains,  the  water  will  be 
more  or  less  turbid  or  impure,  and  may  have  to  be  allowed 
to  run  to  waste.  Where  the  average  supply  of  a  stream  is 
more  than  sufficient  to  meet  all  requirements,  more  or  less 
storage  is  still  required  to  enable  pure  water  to  be  supplied 
whilst  the  river  is  in  flood  and  its  waters  turbid  and  possibly 
polluted.  Wherever  the  water  collected  requires. to  be 
filtered  before  being  delivered  to  the  consumer,  reservoirs 
for  "  settling  "  are  an  almost  indispensable  adjunct  to  the 
filter  beds. 

Such  "  settling "  reservoirs  retard  the  clogging  of  the 
pores  of  the  sand  in  the  filter  beds,  and  therefore  enable 
the  filters  to  work  for  longer  periods  without  cleansing. 
They  should  be  so  constructed  as  to  allow  of  emptying  and 
cleansing,  but  should  not  be  too  shallow,  otherwise  the 


424  WATER  SUPPLIES 

water  may  become  unpleasantly  warm  in  summer.  A 
water  depth  of  12  to  16  feet  is  usually  recommended.  As 
generally  constructed,  with  sloping  sides,  the  growth  of 
algae  is  favoured.  Vertical  sides  are  preferable. 

Smaller  or  "  service  "  reservoirs  are  often  also  constructed 
in  or  near  the  place  to  be  supplied  with  water,  in  order 
to  enable  a  constant  average  flow  to  be  maintained  to  meet 
the  very  varying  demand  during  the  24  hours.  These  are 
especially  necessary  where  the  water  has  to  undergo  a 
process  of  nitration,  in  order  that  the  process  may  be 
uniformly  continuous.  Without  such  a  service  reservoir, 
during  the  period  of  greatest  demand  imperfectly-filtered 
water  would  pass  into  the  mains,  unless  filter  beds  of  an 
otherwise  unnecessarily  large  area  had  been  provided. 
These  reservoirs  are  also  commonly  used  when  water  is 
raised  by  pumping.  Without  such  storage  it  is  evident  that 
pumping  would  "have  to  be  continuous,  and  that  the  rate 
would  have  to  vary  with  the  demand,  whereas  with  a 
service  reservoir  the  pumping  engines  may  work  at  a 
uniform  speed,  and  for  only  a  portion  of  the  24  hours. 

When  the  source  from  which  water  is  derived  is  at  a 
considerable  elevation,  and  long  lengths  of  main  convey  the 
water  in  different  directions,  as  to  villages  and  -towns 
en  route  to  its  ultimate  destination,  service  reservoirs  are 
often  constructed  at  elevated  points,  not  only  to  break  the 
pressure,  but  to  enable  smaller  mains  to  be  used.  Without 
these  reservoirs  the  mains  would  have  to  be  capable  of 
supplying  the  maximum  consumption,  whereas  with  storage, 
the  mains,  as  far  as  the  reservoirs,  need  only  be  capable  of 
delivering  the  average  demand.  As  the  maximum  hourly 
consumption  may  be  twice  the  mean  consumption,  the 
difference  in  first  cost,  where  the  mains  are  of  any  length, 
is  very  considerable. 

Another  very  important  advantage  of  such  reservoirs  is 
that  in  case  of  fire  there  is  a  reserve  of  water  instantly 
available.  This  is  especially  valuable  in  connection  with 


THE  STORAGE  OF  WATER  425 

the  supply  of  small  towns,  villages,  mansions,  and  farms, 
since  the  amount  of  water  likely  to  be  used  in  case  of  an 
outbreak  of  fire  would  be  a  large  fraction  of,  or  might  even 
exceed  that  of  the  whole  capacity  of  the  mains,  whereas  in 
large  towns  the  increased  demand  would  only  be  a  small 
fraction  of  the  average  supply. 

The  amount  of  storage  necessary  and  its  character  de- 
pends upon  the  mode  of  supply,  and  whether  by  gravitation 
or  by  pumping.  Writing  of  these  two  classes  of  waterworks, 
Burton,  in  his  work  on  The  Water  Supply  of  Towns, 
says :  — 

Gravitation  works  to  be  complete  must  consist  of — 

1.  Either  a  high-level  impounding  reservoir,  or  a  high- 

level  intake  with  a  settling  reservoir. 

2.  Filter  beds. 

3.  A  service  reservoir  near  the  impounding  or  settling 

reservoir,  or,  if  there  is  high  land  conveniently 
situated,  a  reservoir  as  near  as  possible  to  the  town 
or  within  it,  or  one  or  more  high-level  tanks  within 
the  town. 

4.  A  distributing  system. 

A  pumping  system  may  consist  of — 
A. — 1.  A  comparatively  low-level  intake. 

2.  One  or  more  settling  reservoirs. 

3.  A  set  of  filter  beds. 

4.  A  pumping  station,  with 

5.  A  high-level  reservoir  or  tank  near  or  within  the 
town,    holding    enough    to   compensate    for    the   in- 
equality  of  the   consumption   during   24   hours. 

6.  A  distributing  system. 

B. — Where  there  is  no  land  for  a  high-level  reservoir,  and  a 
high-level  tank  on  an  artificial  support  to  hold 
enough  water  to  compensate  for  the  variation  in 
consumption  during  24  hours  is  considered  imprac- 
ticable. 
1,  A  comparatively  low-level  intake. 


426  WATER  SUPPLIES 

2.  One  or  more  settling  reservoirs. 

3.  A  set  of  filter  beds. 

4.  A  low-level  service  reservoir. 

5.  A  pumping  station  with  engines  pumping  directly 
into 

6.  A  distributing  system. 

C. — When  the   intake   is  so   low   that  the   water  will   not 
gravitate     to     any     convenient     place     for     settling 
reservoirs  and  filtering  beds,  and  there  is  room  for 
these  only  on  low  ground. 
1.  A  low-level  intake. 

2.  An  intake  pumping  station  with  engines  pumping 
into 

3.  One  or  more  settling  reservoirs. 

4.  A  set  of  filter  beds. 

.  5.  Main  pumping  station  with  engines  pumping  into 

6.  A  high-level  reservoir  on  a  high  artificial  support, 
and 

7.  A  distributing  system. 

D. — The  same  as  before,  C,  up  to  5,  but 

5.  A  low-level  service  reservoir. 

6.  Pumping  station,  with  engines  pumping  into 

7.  A  distributing  system.- 

The  last  case,  as  that  of  B,  occurs  where  there  is  no 
natural  site  for  a  high-level  reservoir,  and  where  a  high- 
level  tank  of  sufficient  size  on  an  artificial  support  would 
be  too  expensive,  or  is,  for  any  other  reason,  impracticable. 

Under  peculiar  circumstances  modifications  of  these 
systems  may  be  and  are  adopted,  and,  of  course,  when  the 
low-level  intake  is  a  well  or  spring  yielding  water  invariably 
pellucid,  the  settling  reservoirs  and  filter  beds  are  dispensed 
with,  and  the  system  is  much  simplified,  the  water  being 
forced  directly  into  a  high-service  reservoir  or  even  into  the 
distributing  mains. 

Impounding  reservoirs  must  be  of  ample  size,  not  only  to 
meet  present  demands,  but  also  such  increased  demand  as 


THE  STORAGE  OF  WATER  427 

may  arise  in  the  more  immediate  future.  Where  large 
works  are  being  constructed  50  years  is  not  an  unreasonable 
length  of  time  to  look  forward  to,  and  as  a  minimum  the 
probable  increase  in  30  years  should  be  provided  for.  Many 
towns  have  been  recently  subjected  to  immense  incon- 
venience and  anxiety  on  account  of  this  neglect,  or  from 
under-estimating  the  growth  of  the  population  and  the 
consequent  increased  demand  for  water. 

The  conditions  which  affect  the  decision  as  to  the  size 
of  settling  and  service  reservoirs  are  of  a  different  character, 
but  probably  the  most  important  is  the  effect  of  storage. 
This  varies  somewhat  with  the  character  of  the  water; 
speaking  generally,  the  purer  the  water  the  less  the  liability 
to  change.  In  natural  reservoirs,  or  lakes,  water  is  less 
prone  to  be  infested  by  organisms,  which  affect  the  odour 
and  taste,  than  in  artificially-constructed  reservoirs.  Pure 
surface  water  contains  too  little  organic  matter  to  favour 
the  growth  of  these  algae  and  fungi,  and  the  effect  of  storage 
is  beneficial  rather  than  otherwise ;  yet  cases  are  recorded 
where  very  pure  waters  have  developed  an  objectionable 
odour  and  taste.  These  growths  are  usually  found  to  occur 
in  reservoirs  storing  water  collected  from  gathering  grounds 
which  are  in  part  cultivated.  The  small  amount  of 
manurial  matter,  or  the  products  of  its  oxidation  taken  up 
by  the  water,  supplies  constituents  necessary  to  the  growth 
and  multiplication  of  these  low  forms  of  life.  Peaty  water 
tends  to  lose  its  colour  if  long  stored,  probably  from  the 
action  of  light,  but  the  observers  for  the  Massachusetts 
Bo>ard  of  Health,  who  have  very  fully  studied  the  effect  of 
storage,  found  that  12  months'  exposure  was  necessary  to 
completely  bleach  such  water.  They  found  that  surface 
waters,  by  storing,  suffered  no  change  in  the  amount  of 
ammonia  and  nitrates  present,  but  in  other  waters  the 
nitrates  were  slightly  reduced.  Investigating  waters  taken 
from  various  depths  from  a  deep  but  small  lake,  they 
concluded  that  vertical  circulation  took  place  during  the 


428  WATER  SUPPLIES 

winter  months,  but  that  during  the  summer  this  was  in 
abeyance,  and  that  the  water  at  the  bottom  of  the  lake 
remained  stagnant.  When  the  air  is  colder  than  the  water, 
the  surface  of  the  latter  will  cool,  becoming  at  the  same  time 
denser  and  tending  to  sink ;  when  the  air  is  warmer  than 
the  water,  or  the  latter  is  exposed  to  the  direct  action  of 
the  sun's  rays,  the  surface  will  become  heated,  and,  decreas- 
ing in  density,  will  retain  its  position.  This,  of  course, 
applies  to  water  stored  in  large  or  small  reservoirs,  provided 
the  water  is  exposed  to  the  air.  The  result  of  the  stagna- 
tion is  probably  very  slight  in  waters  of  great  hygienic 
purity,  but  in  waters  containing  organic  matter  the  free 
oxygen  disappears,  the  water  deteriorates,  free  ammonia 
increasing  in  amount,  especially  at  depths  below  20  feet, 
and  at  such  times  samples  of  water  from  near  the  top  and 
near  the  bottom  may  yield  very  different  results  upon 
analysis. 

Ground  water  when  stored  in  open  reservoirs  is  said  to 
"  deteriorate  at  all  seasons  of  the  year."  The  albumenoid 
ammonia,  or  rather  the  organic  matter  yielding  ammonia 
upon  distillation  with  alkaline  permanganate,  increases, 
and  in  spring  and  summer  the  free  ammonia  becomes 
excessive,  and  at  the  same  time  nitrates  are  reduced.  The 
micro-organisms,  which  in  the  water  at  its  source  are  few 
in  number,  increase  rapidly,  so  that  they  may  even  be  in 
excess  of  those  found  in  much  more  impure  waters.  The 
same  water  when  kept  in  covered  tanks  is  said  to  suffer  but 
an  inappreciable  change ;  this  is  attributed  to  the  absence 
of  light  and  the  difficulty  of  access  of  air-conveyed  microbes. 
I  have  frequently  observed,  however,  that  the  waters  taken 
from  a  whole  series  of  wells  over  a  definite  area  yielded 
much  better  results  both  chemically  and  bacteriologically 
when  examined  in  winter  than  when  collected  in  summer. 
In  small  open  tanks  through  which  water  is  constantly 
passing,  the  water  undergoes,  as  a  rule,  but  little  change, 
but  numerous  instances  are  recorded  of  the  rapid 


THE  STORAGE  OF  WATER  429 

persistent  growth  of  organisms  even  in  service  tanks.  This 
is  almost  certainly  prevented  by  thoroughly  cleansing  and 
covering  the  tanks.  One  organism,  however,  grows  better 
in  the  dark  than  in  the  light,  the  "  Crenothrix,"  and 
occasionally  gives  rise  to  trouble  by  imparting  a  nauseous 
odour  and  taste  to  the  water.  As  this  fungus  requires  for 
its  growth  both  protoxide  of  iron  and  organic  matter,  a 
water  in  which  it  can  nourish  is  not  desirable  for  a 
domestic  supply. 

The  results  of  all  the  observations  which  have  been  made 
on  storage  as  affecting  the  size  of  service  reservoirs  lead  to 
the  conclusion  that  it  is  desirable  to  reduce  this  storage  to 
the  minimum  compatible  with  safety.  It  is  only  necessary, 
therefore,  to  consider  what  capacity  is  required  for  compen- 
sating for  the  inequality  of  the  hourly  consumption,  and 
for  a  reserve  in  case  of  fire. 

Inequality  of  Hourly  Consumption. — Whilst  the  maxi- 
mum consumption  for  a  whole  month  rarely  exceeds  by  30 
per  cent,  the  mean  for  the  year,  the  maximum  hourly 
consumption  may  exceed  this  by  100  per  cent.  Mr.  J. 
Parry,  M.Inst.C.E.,  found  in  Liverpool  during  1893  that 
the  maximum  weekly  consumption  took  place  in  July,  when 
it  was  15  per  cent,  above  the  mean,  and  that  the  minimum 
occurred  in  November  and  December,  and  was  9  per  cent, 
below  the  mean.  The  highest  hourly  rate  at  which  water 
was  delivered  was  between  10  and  11  A.M.  on  6th  July,  when 
the  delivery  was  at  the  rate  of  50  gallons  per  head,  or  85 
per  cent,  above  the  average  for  the  year.  Mr.  Parry  says, 
"  The  weather  at  the  time  was  exceptionally  warm,  and  it 
is  not  probable  that  the  difference  between  the  mean  and 
maximum  rate  of  discharge  could  ever  exceed  this  amount." 
Experiments  which  have  been  conducted  in  Germany,  how- 
ever, have  shown  a  greater  variation  than  this.  Taking 
the  mean  of  a  number  of  records  from  various  waterworks, 
and  taking  the  mean  annual  consumption  as  1.0,  the 
maximum  daily  discharge  was  1.4,  and  the  maximum 


436  WATER  SUPPLIES 

hourly  2.1.  The  minimum  flow  is  of  trifling  importance; 
in  nearly  all  cases  where  waste  is  prevented  as  much  as 
possible,  the  flow  during  some  portion  of  the  night 
approaches  zero>. 

It  is  easily  demonstrated  that  a  service  reservoir  capable 
of  holding  7  hours'  mean  supply  would  be  amply  large  to 
compensate  for  all  inequalities  in  the  demand  for  ordinary 
purposes,  but  in  small  towns  there  would  be  but  a  small 
reserve  in  case  of  fire. 

Reserve  for  Fire  Extinction. — In  many  cases  little  reserve 
for  this  purpose  is  required,  since  by  means  of  a  by-pass  or 
by  increased  pumping  all  the  necessary  water  may  be 
rendered  available.  Where  such  is  not  the  case  Burton 
gives  a  formula  for  estimating  roughly  the  amount  of  water 
which  should  be  stored  for  the  special  purpose  of  fire 
extinction :  — 

Q  -  200  JP, 

where  Q  =  the  quantity  to  be  stored  in  cubic  feet  and  P 
the  population  of  the  town.  This  formula  gives  125,000 
gallons  as  the  storage  for  this  purpose  in  a  town  of  10,000 
population,  and  1,250,000  for  a  city  of  1,000,000  inhabi- 
tants, or  10  hours'  mean  supply  for  the  former  and  1  hour 
for  the  latter. 

To  compensate  for  the  inequalities  in  the  demand  for 
domestic  purposes  and  for  use  in  case  of  fire,  17  hours' 
storage  in  the  smaller  town  and  8  hours'  in  the  larger 
would  suffice.  In  any  case  1  day's  supply  should  be  ample. 
This  is  a  reasonable  mean  between  the  estimates  of  those 
who  recommend  6  or  7  hours'  storage  and  those  who  would 
provide  two  or  three  days'  storage.  Where  such  an  amount 
cannot  be  kept  in  reserve  the  pumping  machinery  must  be 
sufficiently  powerful  to  supply  the  additional  quantity, 
or  if  the  water  flows  by  gravitation  from  impounding 
reservoirs  the  service  mains  must  be  large  enough  to 
carry  it. 


THE  STORAGE  OF  WATER  431 

In  moderate-sized  towns  the  service  reservoir  may  be 
placed  upon  an  elevated  tower  of  brick,  stone,  or  ironwork. 
The  tank  should  be  constructed  of  wrought  or  cast  iron, 
covered  to  exclude  light,  heat,  and  dust,  and  it  should  be 
divided  into  two  or  more  compartments  for  convenience  in 
cleansing.  Where  placed  upon  a  natural  elevation  it  may 
be  of  brickwork  rendered  in  cement.  In  larger  towns, 
where  there  is  no  elevated  ground  sufficiently  near,  and  the 
erection  of  tanks  on  towers  would  be  too  expensive,  storage 
must  be  dispensed  with,  and  the  mains,  if  a  gravitation 
system,  must  be  sufficiently  large  to  supply  the  maximum 
demand ;  or  if  a  pumping  system,  the  pumping  engines 
must  be  so  constructed  that  the  pumping  corresponds 
exactly  with  the  consumption.  A  constant  pressure  may 
be  obtained  from  a  stand  pipe  or  by  means  of  an  air 
chamber.  A  float  within  the  stand  pipe  can  be  made  to 
adjust  the  speed  of  the  engine  or  the  stroke  of  the  pumps, 
decreasing  when  the  water  rises  and  increasing  when  the 
water  falls,  or  the  pressure  in  the  air  chamber  may  be 
caused  to  automatically  check  or  accelerate  the  action  of 
the  pumps. 

In  Chapter  II.  reference  was  made  to  the  storage  of  rain 
water  for  the  supply  of  cottages,  farms,  and  mansions. 
Denton  recommends  that  the  tanks  used  should  be  capable 
of  holding  120  days'  supply,  but  few  mansions  or  farms 
have  sufficient  roof  area  to  allow  of  anything  like  this 
quantity  being  collected  even  in  the  wettest  seasons,  whilst 
the  average  cottage  could  not  collect  more  than  half  this 
amount.  A  tank  capable  of  holding  one-third  of  the  rainfall 
is  probably  as  large  as  ever  could  be  filled,  and  it  is  useless 
constructing  tanks  to  hold  more  water  than  can  be  collected, 
and  absurd  to  think  of  compensating  for  a  too  limited 
collecting  area  by  increasing  the  storage  capacity.  Only 
the  excess  of. rainfall  over  and  above  that  used  during  the 
rainy  season  can  be  stored,  and  the  smaller  the  collecting 


432  WATER  SUPPLIES 

areas,  the  smaller  will  be  the  surplus  and  the  smaller  the 
tank  which  is  necessary  for  storing  it. 

Rain-water  tanks  are  usually  placed  underground,  where 
it  is  almost  impossible  to  ascertain  if  they  are  water-tight. 
They  are  difficult  of  access  and  more  difficult  to  cleanse. 
Tanks  fitted  with  rain-water  separators  and  filters  can  be 
constructed  above  ground,  and  are  in  every  respect  prefer- 
able. Underground  tanks,  if  cut  out  of  solid  chalk  or 
sandstone,  merely  require  lining  with  cement.  Tanks  con- 
structed in  pervious  soil  must  be  made  of  brickwork  in 
cement  and  be  rendered  in  cement,  and  arched  over  with 
the  same  materials. 

Where  water  has  to  be  pumped  for  single  houses  or  small 
groups  of  houses,  in  calculating  the  amount  of  storage 
necessary  it  must  be  remembered  that  the  inequalities  in 
the  demand  will  vary  .to  a  much  greater  extent  than  when 
a  whole  village  or  town  is  being  supplied.  For  this  reason 
the  tank  must  be  larger  in  proportion,  and  also  because 
provision  must  be  made  for  such  contingencies  as  the 
breakdown  of  the  pumping  machinery  and  an  outbreak  of 
fire.  A  comparatively  small  qiiantity  of  water  at  the 
moment  when  a  fire  is  discovered  may  suffice  to  prevent  a 
conflagration ;  hence,  if  possible,  some  provision  should  be 
made  to  render  a  supply  readily  available.  It  has  already 
been  pointed  out  that  water  tends  to  deteriorate  in  quality 
when  stored  in  tanks;  therefore  it  is  better,  if  possible,  to 
have  a  separate  reservoir  for  storing  water  for  fire 
extinction.  Where  valuable  property  is  concerned,  as  in 
mansions  and  large  farms,  the  additional  expense  incurred 
may  prove  a  valuable  investment.  The  size  of  tank  required 
if  the  water  is  to  be  utilised  for  all  purposes  will  depend 
upon  (1)  the  amount  desired  to  be  stored  in  case  of  fire; 
(2)  whether  the  pumping  is  constant,  as  by  a  ram,  turbine, 
or  water-wheel,  or  (3)  intermittent  and  at  irregular 
intervals,  as  when  the  pumps  are  worked  by  a  wind  engine, 
or  (4)  intermittent  but  at  regular  intervals,  as  when  manual 


THE  STORAGE  OF  WATER  433 

labour  or  some  form  of  gas,  oil,  hot-air  or  steam  engine 
is  used.  Leaving  (1)  out  of  consideration,  with  the  second 
or  fourth  arrangement  a  tank  holding  2  to  4  days'  domestic 
supply  would  be  ample.  With  the  third  system  there 
should  be  storage  provided  for  from  7  to  12  days'  domestic 
If  the  same  tank  is  required  to  store  water  for  fire 
extinction,  it  must  be  larger,  according  to  the  quantity 
considered  necessary  for  use  in  such  an  emergency.  Where 
there  is  an  ample  amount  of  water  at  the  intake  and  a 
steam  or  similar  engine  is  used  for  pumping,  the  fire  reserve 
needs  not  be  large,  since  the  engines  can  speedily  be  set  to 
work  and  the  reserve  supplemented. 

The  possibility  of  water  being  injuriously  affected  by  the 
materials  of  which  small  tanks  are  often  made  has  been 
mentioned  in  Chapter  IX.,  and  the  advantages  and  dis- 
advantages of  storing  water  in  house  cisterns,  necessitated 
by  an  "  intermittent  "  public  supply,  will  be  referred  to 
in  the  next  chapter  on  "  The  distribution  of  water/' 

Where  the  water  supply  is  "  constant,"  there  should  be 
no  necessity  for  storage  cisterns  in  private  houses.  But 
where  the  supply  is  only  "  constant  "  in  theory,  and  not 
in  actual  practice,  as  in  many  parts  of  London  during 
seasons  of  drought,  these  cisterns  must  be  retained ;  but 
in  such  cases  draw-off  taps  should  be  affixed  to  the  rising 
main  for  the  supply  of  water  for  dietetic  purposes.  Of 
course  this  cistern  should  not  directly  supply  any  water- 
closet  or  place  of  similar  character.  Where  the  water 
supply  is  "  intermittent,"  a  storage  cistern  capable  of 
holding  one  day's  supply  is  absolutely  necessary. 


CHAPTER  XXIII. 

THE  DISTRIBUTION  OF  WATER. 

IT  is  now  generally  admitted  that  no  public  supply 
is  entirely  satisfactory  unless  the  mains  are  constantly  full 
and  under  pressure' — that  is,  unless  the  supply  be 
"  constant."  Under  the  mistaken  impression  that  the 
amount  of  water  supplied  would  be  economised,  most  of  the 
older  waterworks  only  admitted  water  to  the  mains  for  one 
or  more  hours  daily,  cluring  which  time  the  house  cisterns 
were  filled,  and  the  amount  used  in  each  house  was  limited 
by  the  capacity  of  its  cistern.  This  "  intermittent "  system 
is  now  being  gradually  abandoned,  since,  as  we  have  already 
seen,  a  constant  supply  when  properly  superintended  is 
equally,  if  not  actually  more  economical.  The  risk  of  the 
water  becoming  polluted  in  the  mains  (vide  Chapter  XI.) 
is  also  reduced  to  a  minimum  by  keeping  them  constantly 
full  and  under  pressure,  and  in  case  of  fire  a  supply  of  water 
is  more  readily  available.  As  the  whole  day's  supply  has 
not  to  be  delivered  in  a  very  few  hours,  the  mains  need 
not  be  so  capacious,  and  house  cisterns  are  no  longer 
necessary.  The  disadvantages  of  such  cisterns  are  numerous. 
Usually  placed  in  inaccessible  situations,  uncovered  or 
imperfectly  covered,  and  constructed  of  unsuitable  material, 
they  are  a  frequent  cause  of  the  water  becoming  fouled,  or 
of  its  becoming  unpalatable  from  the  heat,  and  a  severe 
frost  is  more  likely  to  cut  off  the  supply.  For  these  reasons 
no  engineer  would  now  suggest  the  adoption  of  the  "  inter- 

(434) 


THE  DISTRIBUTION  OF  WATER  435 

mittent  "  system,  and  it  is  to  be  hoped  that  where  adopted 
it  will  soon  be  abandoned,  and  that  every  house  over  the 
areas  supplied  will  have  a  constant  service  at  high  pressure. 

Whilst  open  conduits  may  convey  water  from  the  intake 
to  the  filter  beds,  covered  conduits  or  cast-iron  pipes  must 
be  used  for  carrying  water  from  the  filter  beds  to  the 
service  reservoirs.  Where  the  pressure  is  but  slight  earthen- 
ware pipes  may  be  used,  or  masonry,  or  brickwork,  but 
iron  will  probably  be  cheaper  than  the  latter.  For  such 
aqueducts  a  fall  of  5  feet  per  mile  will  suffice  for  pipes  of 
2  feet  in  diameter,  and  a  fall  of  17  feet  should  not  be 
exceeded.  Earthenware  pipes  are  not  desirable,  but  if  used 
must  be  laid  in  a  well-puddled  or  concrete-lined  water-tight 
trench,  and  if  valleys  have  to  be  crossed  the  syphon  portion 
must  be  of  cast-iron  to  withstand  the  pressure,  and  means 
should  be  provided  to  wash  out  the  syphon  at  its  lowest 
point.  In  pumping  mains  the  velocity  of  the  water  should 
be  about  2  feet  per  second,  and  in  no  case^  exceed  2J  feet. 
To  allow  for  growth  of  population,  increased  demand  and 
corrosion  of  pipes,  a  velocity  of  1J  feet  in  the  first  instance 
will  probably  be  as  large  as  can  be  adopted  with  safety. 
(The  power  expended  in  pumping  varies  directly  as  the  cube 
of  the  velocity  ;  hence,  what  is  saved  by  using  smaller  pipes 
is  more  than  lost  in  the  cost  of  power.)  In  gravitation 
mains  a  little  higher  velocity,  3  feet  per  second,  is 
permissible. 

For  calculating  the  velocity  with  which  water  will  pass 
through  castoron  mains  when  first  laid,  Eytelwein's  formula 
is  fairly  reliable:  — 


where  V  =  the  velocity  in  feet  per  second  ;  d,  the  diameter 
of  the  pipe  ;  A,  the  head  of  water  ;  and  I,  the  length  of  the 
pipe  in  feet.  In  new  pipes  ^  =  50,  but  its  value  decreases 
with  the  corrosion,  and  may  sink  as  low  as  32.  The  factor 


436  WATER  SUPPLIES 

50d  may  be  disregarded  in  pipes  more  than  a  few  hundred 
feet  in  length.  Sharp  bends  should  be  avoided,  since  they 
increase  the  friction  and  retard  the  flow.  Where  the  pipes 
follow  the  contour  of  the  ground,  air-valves  should  be 
attached  to  the  highest  points.  All  pipes  used  should  have 
previously  been  tested  and  proved  to  be  capable  of  with- 
standing twice  the  pressure  to  which  it  is  calculated  that 
they  will  be  subjected. 

•  A  "  trunk  "  main  conveys  the  water  from  the  service 
reservoir  to  the  confines  of  the  districts  to  be  supplied.  It 
then  breaks  up  into  "  distributing  "  mains,  one  for  each 
district.  The  "  distributing  "  mains  supply  "  service  " 
mains,  and  from  these  latter  are  taken  the  "  house  service  " 
mains  or  "  communication  pipes."  No  service  main  should 
be  less  than  3  inches  in  diameter,  and  in  towns  it  is  never 
desirable  that  they  should  be  less  than  4  inches.  In  many 
American  cities  the  minimum  is  6  inches. 

For  the  sake  of  economy  mains  of  too  small  diameter 
are  frequently  employed,  and  the  mistake  when  discovered 
is  a  costly  one  to  remedy.  A  common  error  is  to  suppose 
that  the  flow  of  water  varies  only  with  the  sectional  area 
of  the  main,  but  a  glance  at  Eytelwein's  formula  is  sufficient 
to  disprove  this.  For  example,  with  a  head  of  100  feet 
and  a  main  10,000  feet  long,  what  will  be  the  flow  from  a 
3-inch  and  a  6-inch  main  respectively1?  In  the  first  case — 

V  =  50  ^-25  x  100  =  2-5  feet  per  second, 

10,000 
and  the  flow  =  V  x  <i2-7854  =  -1227  cubic  feet  per  second. 

In  the  second  case — 

V  =  50  ^.5  x  100  =  3-5  feet  per  second. 

10,000 
and  the  flow  will  be  -687  cubic  feet  per  second. 

The  loss  of  head  on  account  of  friction  is  a  still  more 
serious  matter  when  it  is  intended  that  the  water  shall  be 


THE  DISTRIBUTION  OF  WATER  437 

available  for  fire-extinguishing.  Thus,  to  quote  an  example 
from  Merryweather's  Water  Supply  to  Mansions :  "  The 
passage  of  300  gallons  of  water  per  minute  through  500 
yards  of  4-inch  pipe  will  absorb  in  friction  a  head  of  172 
feet,  whereas  if  5-inch  pipe  be  used,  only  57  feet  will  be 
absorbed;  that  is,  assuming  the  reservoir  to  be  200  feet 
above  the  house,  if  you  lay  the  4-inch  pip©  500  yards  long, 
when  delivering  300  gallons  per  minute  the  head  or 
pressure  on  the  jets  will  only  be  28  feet,  and  the  height 
of  the  jets  about  20  feet,  but  with  the  5-inch  pipe  the  head 
will  be  143  feet,  and  the  height  of  the  jet  will  be  100 
feet;  in  each  case  the  balance  of  the  200  feet  is  absorbed 
by  the  friction  of  the  water  against  the  sides  of  the  pipe/' 

In  certain  towns — Liverpool,  for  instance — special  mains 
are  laid  through  the  business  parts  for  supplying  water 
for  extinguishing  fires.  In  the  residential  parts  the  same 
mains  act  as  fire  mains  as  well  as  service  mains. 

Cast-iron  pipes  are  practically  universally  used  for  dis- 
tributing and  service  mains,  and  these  should  be  properly 
varnished  within  and  without.  This  varnish  generally 
imparts  to  the  water,  for  a  time,  a  tarry  flavour,  which, 
although  objectionable,  is  not  injurious.  After  long 
keeping  the  varnish  imparts  less  flavour  to  the  water,  but 
pipes  so  kept  are  not  so  durable  as  those  laid  down  soon 
after  being  coated.  Turned  and  bored  joints  are  cheapest, 
but  engineers  are  divided  in  opinion  as  to  whether  these 
or  joints  made  with  lead  are  the  best.  The  latter  are 
more  flexible,  and  should  alone  be  used  where  the  ground 
is  not  firm  or  where  there  is  danger  of  subsidence.  Where 
turned  and  bored  joints  are  used,  an  occasional  lead  joint 
should  be  introduced  to  allow  for  the  elongation  and 
contraction  caused  by  changes  of  temperature. 

To  prevent  the  undue  influence  of  the  variations  of  the 
earth's  temperature,  Rawlinson  says  that  the  mains  should 
be  laid  at  a  minimum  depth  of  not  less  than  3  feet.  Other 


438  WATER  SUPPLIES 

engineers  give  2  feet  6  inches  as  the  minimum,  but  in 
England  the  water  in  mains  at  the  latter  depth  has  become 
frozen  during  very  severe  winters.  The  latter  is  the  depth 
of  cover  required  in  most  large  towns,  but  in  Manchester 
3  feet,  and  in  Bradford  2  feet  is  adopted  as  the  minimum. 
In  all  systems  of  distribution  it  is  not  only  of  the 
highest  importance  to  have  all  the  mains  of  ample  size, 
but  that  the  service  mains  be  so  arranged  that  there 
shall  be  few  or  no  "  dead  ends/'  and  that,  as  far  as  possible, 
all  valves  and  connections  should  be  placed  so  that  in  case 
of  accident  to  one  main  the  supply  may  be  kept  up  from 
another. 

— The  "  dead  end  "  system  had  many  apparent  advantages 
which  caused  it  to  be  generally  used.  Parts  of  the  system 
could  easily  be  cut  off  when  necessary  by  a  single  valve, 
and  the  sizes  of  the  mains  could  be  readily  calculated.  It 
was  soon  found,  however,  that  the  stagnant  water  in  the 
ends  became  deteriorated  in  quality,  and  it  has  sometimes 
been  suspected  that  where  disease  germs  had  gained  access 
to  the  mains  they  had  been  able  to  multiply  in  the  still 
water.  This  can  in  part  be  prevented  by  placing  flushing 
valves  at  the  ends  of  the  mains,  but  these  require  constant 
attention,  and  if  regularly  opened  cause  the  waste  of  much 
water.  On  the  whole  it  seems  preferable  to  adopt  some 
form  of  interlacing  system,  in  which  the  ends  of  the  mains 
are  connected  together  wherever  possible.  By  a  proper 
arrangement  of  sluices  any  small  portion  of  the  system  can 
be  cut  off  by  closing  two  valves,  whenever  such  closure  is 
necessary  for  the  repair  of  that  portion.  Formerly  the 
supply  to  a  district  had  to  be  stopped  every  time  the  main 
was  being  tapped,  but  ferrule  machines  have  been  con- 
structed and  are  now  largely  used,  which  enables  the 
"  house  service  "  mains  to  be  attached  to  the  service  mains 
whilst  the  latter  are  full  of  water  under  pressure.  Where 
this  machine  is  used  the  occasions  upom  which  it  is 


THE  DISTRIBUTION  OF  WATER  439 

necessary  to  cut  off  any  part  of  the  system  are  very  rare. 
It  is  obvious  that  water-waste  preventers,  such  as  Deacon's, 
cannot  be  used  on  any  portion  of  the  interlacing  system. 
They  must  be  attached  to  near  the  ends  of  the  distributing 
mains,  and  each  controlled  by  a  valve  beyond  the  meter, 
and  there  should  be  a  separate  distributing  main  for  each 
district  of  from  2,000  to  5,000  people. 

House  service  pipes  may  be  of  lead,  tin-lined  lead,  tin- 
lined  iron,  cast  iron  or  wrought  iron,  enamelled  or 
galvanised. 

Lead  pipe  is  most  generally  applicable,  but  it  should 
not  be  used  with  waters  which  contain  very  little  or  no 
carbonates.  Such  waters  are  usually  very  soft,  but  it  is 
desirable  to  remember  that  occasionally  very  soft  waters 
contain  carbonate  of  soda  and  have  no  action  on  lead,  and 
that  hard  waters  sometimes  are  free  from  carbonates  and 
then  act  upon  this  metal.  To  prevent  this  action  tin-lined 
lead  pipe  was  introduced,  but  has  not  answered  the  expecta- 
tions of  its  makers.  It  possesses  little  advantage  over  lead 
pipe,  and  has  many  disadvantages,  besides  being  much 
dearer.  Still  more  recently  a  tin-lined  iron  pipe  has  been 
placed  in  the  market,  and  so  far  as  present  experience 
enables  its  merits  to  be  appraised,  it  would  appear  to 
possess  many  advantages  over  all  other  kinds  of  pipe.  It 
consists  of  strong  wrought-iron  tube  with  an  internal  lining 
of  block  tin,  and  the  lengths  are -joined  up  by  screw 
joints,  so  that  the  tin  lining  is  practically  continuous. 

Wrought-iron  pipes  are  cheaper  than  lead,  and  as  easily 
or  more  easily  fitted,  and  admit  of  repairs  and  alterations 
being  made  with  equal  facility,  provided  double  screw 
joints  are  used  at  convenient  points.  They  are,  however, 
very  liable  to  become  choked  by  internal  corrosion.  A 
pipe  1  inch  in  diameter  may  choke  in  from  six  to  ten 
years.  If  galvanised  its  durability  is  much  increased. 
Certain  soft  waters,  however,  possess  the  power  of  dissolv- 


440  WATER  SUPPLIES 

ing  zinc,  and  of  rapidly  corroding  the  iron.  In  such  a  case 
the  tin-lined  iron  pipe  becomes  indispensable,  since  the 
same  waters  invariably  act  upon  lead. 

Where  water  pipes  have  to  be  carried  through  made 
ground  containing  ashes,  spent  lime,  chemical  refuse,  etc., 
they  should  be  protected  by  a  clay  puddle,  concrete,  or 
asphalte  covering,  otherwise  they  will  be  injuriously 
affected. 

To  prevent  the  action  of  frost  a  minimum  depth  of 
3  feet  is  desirable,  and  within  the  house  they  should  be 
placed  in  positions  in  which  the  frost  is  least  likely  to  affect 
them.  No  pipe  will  withstand  the  action  of  frost,  but  lead 
pipes  may  usually  be  frozen  many  times  before  actually 
bursting,  on  account  of  the  ductility  of  the  metal.  The 
split  caused  by  the  expansion  of  the  water  in  the  act  of 
freezing  is  in  all  cases  longitudinal.  In  lead  pipe  the 
metal  bulges  before  splitting.  As  it  is  of  the  highest 
importance  for  the  prevention  of  waste  and  pollution  that 
all  house  connections  should  be  properly  made,  and  the 
fittings  be  of  a  satisfactory  character,  the  regulations  made 
under  the  "  Metropolis  Water  Act,  1871,"  as  to  house 
fittings,  are  given  in  an  appendix,  as  upon  them  are  based 
the  regulations  of  many  other  towns. 

Mr.  T.  Duncanson,  in  his  paper,  already  referred  to,  on 
"  The  Distribution  of  Water  Supplies,"  gives  the  following 
brief  summary  of  the  objects  to  be  aimed  at  in  providing 
a  public  supply  of  water  :  — 

"  (1)  That  a  sufficient  supply  of  wholesome  water  for 
the  reasonable  needs  of  a  community  should  be  provided. 

"  (2)  That  this  water  should  be  so  supplied  that  at  all 
times  there  is  sufficient  pressure  to  reach  the  highest  part 
of  every  house. 

"  (3)  That  all  piping  and  fittings  should  be  of  such  a 
character  and  so  arranged  as  to  reduce  the  probability  of 
failure  to  a  minimum. 


THE  DISTRIBUTION  OF  WATER  441 

"  (4)  That  there  should  be  an  effective  system  for  the 
prompt  detection  of  waste  when  it  does  occur. 

"  (5)  That  all  arrangements  should  be  of  such  a  character 
as  to  reduce  the  inconvenience  arising  from  necessity  for 
repairs  to>  a  minimum. 

"  (6)  That  all  appliances  for  the  consumption  of  water 
should  be  so  arranged  as  to  use  it  in  the  most  efficient  way. 

"  The  extent  to  which  a  public  supply  meets  the  above 
requirements  will  be  a  fair  index  of  its  character." 


APPENDIX  TO  CHAPTER  XXIII. 


REGULATIONS  MADE  UNDER  THE  METROPOLIS  WATER  ACT,  1871. 


1.  No  "communication  pipe"  for  the  conveyance  of  water  from  the 
waterworks  .of  the  Company  into  any  premises  shall  hereafter  be  laid 
until  after  the  point  or  place  at  which  such  "communication  pipe"  is 
proposed  to  be  brought  into  such  premises  shall  have  had  the  approval 
of  the  Company. 

2.  No  lead  pipe  shall  hereafter  be  laid  or  fixed  in  or  about  any 
premises  for  the   conveyance   of,   or  in   connection  with  the   water 
supplied  by  the  Company  (except  when,  and  as  otherwise  authorised  by 
these  regulations,  or  by  the  Company),  unless  the  same  shall  be  of 
equal  thickness  throughout,  and  of  at  least  the  weight  following,  that 
is  to  say  : — 


Internal  Diameter  of  Pipe 
in  inches. 

Weight  of  Pipe  in  pounds  per 
lineal  yard. 

§  inch  diameter 

5    lb.  per  lineal  yard 

1 

6 

? 

| 

> 

7J 

, 

1 

t 

9          -  , 

, 

1 

> 

12 

1* 

16            , 

'   .      ' 

3.  Every  pipe  hereafter  laid  or  fixed  in  the  interior  of  any  dwelling- 
house  for  the  conveyance  of,  or  in  connection  with,  the  water  of  the 
Company,  must,  unless  with  the  consent  of  the  Company,  if  in  contact 
with  the  ground,  be  of  lead,  but  may  otherwise  be  of  lead,  copper,  or 
wrought  iron,  at  the  option  of  the  consumer. 

4.  No  house  shall,  unless  with  the  permission  of  the  Company  in 
writing,   be   hereafter  fitted   with  more   than   one   "  communication 
pipe." 

(442) 


APPENDIX  TO  CHAPTER  XXIII  443 

5.  Every  house  supplied  with  water  by  the  Company  (except  in 
cases  of  stand  pipes)  shall  have  its  own  separate  "  communication  pipe," 
provided  that,  as  far  as  is  consistent   with  the  special  Acts  of  the 
Company,  in  the  case  of  a  group  or  block  of  houses,  the  water-rates  of 
which  are  paid  by  one  owner,  the  said  owner  may,  at  his  option,  have 
on«  sufficient  "communication  pipe"  for  such  group  or  block. 

6.  No  house  supplied  with  water  by  the  Company  shall  have  any 
connection  with  the  pipes  or  other  fittings   of  any  other  premises, 
except  in  the  case  of  groups  or  blocks  of  houses,  referred  to  in  the 
preceding  regulation. 

7.  The  connection  of  every  "communication  pipe"  with  any  pipe 
of  the"  Company  shall  hereafter  be  made  by  means  of  a  sound  and 
suitable  brass  screwed  ferrule  or  stop-cock  with  union,  and  such  ferrule 
or  stop-cock  shall  be  so  made  as  to  have  a  clear  area  of  water-way  equal 
to  that  of  a  half -inch  pipe.     The  connection  of  every  "communica' 
tion  pipe "   with   the  pipes  of  the   Company  shall  be  made  by  the 
Company's  workmen,  and  the  Company  shall  be  paid  in  advance  the 
reasonable  costs  and  charges  of,  and  incident  to,  the  making  of  such 
connection. 

8.  Every  "  communication  pipe "   and  every  pipe  external  to  the 
house,  and  through  the  external  walls  thereof,  hereafter  respectively 
laid  or  fixed  in  connection  with  the  water  of  the  Company,  shall  be  of 
lead,  and  every  joint  thereof  shall  be  of  the  kind  called  "plumbing" 
or  "wiped"  joint. 

9.  No  pipe  shall  be  used  for  the  conveyance  of,  or  in  connection 
with,  water  supplied  by  the  Company,  which  is  laid  or  fixed  through, 
in,  or  into  any  drain,  ash-pit,  sink,  or  manure-hole,  or  through,  in,  or 
into  any  place  where  the  water  conveyed  through  such  pipe  may  be 
liable  to  become  fouled,  except  where  such  drain,  ash-pit,  sink,  or 
manure-hole,  or  any  such  place,  shall  be  in  the  unavoidable  course  of 
such  pipe,  and  then  in  every  such  case  such  pipe  shall  be  passed 
through  an  exterior  cast-iron  pipe  or  jacket  of  sufficient  length  and 
strength,  and  of  such  construction  as  to  afford  due  protection  to  the 
water  pipe. 

10.  Every  pipe  hereafter  laid  for  the  conveyance  of,  or  in  connection 
with,  water  supplied  by  the  Company,  shall,  when  laid  in  open  ground, 
be   laid   at   least   2   feet    6  inches  below  the   surface,   and   shall  in 
every  exposed  situation  be  properly  protected  against  the  effects  of 
frost. 

11.  No  pipe  for  the  conveyance  of,  or  in  connection  with,  water 
supplied  by  the  Company,  shall  communicate  with  any  cistern,  butt, 
or  other  receptacle  used  or  intended  to  be  used  for  rain  water. 

J2.  Every  "  communication  pipe  "  for  the  conveyance  of  water  to 


444  WATER  SUPPLIES 

be  supplied  by  the  Company  into  any  premises  shall  have  at  or  near 
its  point  of  entrance  into  such  premises,  and  if  desired  by  the  consumer 
within  such  premises,  a  sound  and  suitable  stop-valve  of  the  screw- 
down  kind,  with  an  area  of  water-way  not  less  than  that  of  a  half-inch 
pipe,  and  not  greater  than  that  of  the  "  communication  pipe,"  the 
size  of  the  valve  within  these  limits  being  at  the  option  of  the  con- 
sumer. If  placed  in  the  ground  such  "  stop-valve  "  shall  be  protected 
by  a  proper  cover  and  "  guard-box." 

18.  Every  cistern  used  in  connection  with  the  water  supplied  by  the 
Company  shall  be  made  and  at  all  times  maintained  water-tight,  and 
be  properly  covered  and  placed  in  such  a  position  that  it  may  be 
inspected  and  cleansed.  Every  such  existing  cistern,  if  not  already 
provided  with  an  efficient  "ball-tap,"  and  every  such  future  cistern, 
shall  be  provided  with  a  sound  and  suitable  "ball-tap"  of  the  valve 
kind  for  the  inlet  of  water. 

14.  No  overflow  or  waste  pipe  other  than  a  "warning  pipe"  shall 
be  attached  to  any  cistern  supplied  with  water  by  the  Company,  and 
every  such  overflow  or  waste  pipe  existing  at  the  time  when  these 
regulations  come  into  operation  shall  be  removed,  or  at  the  option  of 
the  consumer  shall  be   converted  into  an    efficient   "  warning  pipe," 
within  two  calendar  months  next  after  the  Company  shall  have  given 
to  the  occupier  of,   or  left  at  the  premises  in  which  such  cistern  is 
situated,  a  notice  in  writing  requiring  such  alteration  to  be  made. 

15.  Every  "  warning  pipe "  shall  be  placed  in  such  a  situation  as 
will  admit  of  the  discharge  of  the  water  from  such  "  warning  pipe  " 
being  readily  ascertained  by  the  officers  of  the  Company.     And  the 
position   of    such   "  warning   pipe "   shall    not    be    changed    without 
previous  notice  to  and  approval  by  the  Company. 

16.  No  cistern  buried  or  excavated  in  the  ground  shall  be  used  for 
the  storage  or  reception  of  water  supplied  by  the  Company,  unless  the 
use  of  such  cistern  shall  be  allowed  in  writing  by  the  Company. 

17.  No  wooden  receptacle  without  a  proper  metallic  lining  shall  be 
hereafter  brought  into  use  for  the  storage  of  any  water  supplied  by  the 
Company. 

18.  No  draw-tap  shall  in  future  be  fixed  unless  the  same  shall  be 
sound  and  suitable  and  of  the  "  screw-down  "  kind. 

19.  Every  draw-tap  in  connection  with  any  "stand  pipe"  or  other 
apparatus  outside  any  dwelling-house  in  a  court  or  other  public  place, 
to   supply   any   group  or   number  of   such   dwelling-houses,   shall   be 
sound   and   suitable    and    of    the    "waste-preventer"   kind,    and    be 
protected  as  far  as  possible  from  injury  by  frost,  theft,  or  mischief. 

20.  Every  boiler,  urinal,  and  water-closet,  in  which  water  supplied 
by  the  Company  is  used   (other   than   water-closets   in   which   hand 


APPENDIX  TO  CHAPTER  XXIII  445 

flushing  is  employed),  shall,  within  three  months  after  these  regula- 
tions come  into  operation,  be  served  only  through  a  cistern  or  service- 
box  and  without  a  stool-cock,  and  there  shall  be  no  direct  communication 
from  the  pipes  of  the  Company  to  any  boiler,  urinal,  or  water-closet. 

21.  Every  water-closet  cistern  or  water-closet  service-box  hereafter 
fitted  Or  fixed,  in  which  water  supplied  by  the  Company  is  to  be  used, 
shall  have  an  efficient  waste-preventing  apparatus,  so  constructed  as 
not  to  be  capable  of  discharging  more  than  two  gallons  of  water  at 
each  flush. 

22.  Every  urinal-cistern  in  which  water  supplied  by  the  Company 
is  used  other  than  public  urinal-cisterns,  or  cisterns  having  attached 
to  them  a  self-closing  apparatus,  shall  have  an  efficient  "  waste-pre- 
venting "  apparatus,  so  constructed  as  not  to  be  capable  of  discharging 
more  than  one  gallon  of  water  at  each  flush. 

23.  Every  "down  pipe"  hereafter  fixed  for  the  discharge  of  water 
into   the   pan   or  basin  of  any  water-closet   shall   have   an   internal 
diameter  of  not  less  than  one  inch  and  a  quarter,  and  if  of  lead  shall 
weigh  not  less  than  nine  pounds  to  every  lineal  yard. 

24.  No  pipe  by  which  water  is  supplied  by  the  Company  to  any 
water-closet  shall  communicate  with  any  part  of  such  water-closet,  or 
with  any  apparatus   connected   therewith,  except  the  service-cistern 
thereof. 

25.  No  bath  supplied  with  water  by  the  Company  shall  have  any 
overflow  waste  pipe,  except  it  be  so  arranged  as  to  act  as  a  "  warning 
pipe." 

26.  In  every  bath  hereafter  fitted  or  fixed  the  outlet  shall  be  distinct 
from,  and  unconnected  with,  the  inlet  or  inlets  ;  and  the  inlet  or  inlets 
must  be  placed  so  that  the  orifice  or  orifices  shall  be  above  the  highest 
water-level  of  the  bath.     The  outlet  of  every  such  bath  shall  be  pro- 
vided with  a  perfectly  water-tight  plug,  valve,  or  cock. 

27.  No  alteration  shall  be  made  in  any  fittings  in  connection  with 
the  supply  of  water  by  the  Company  without  two  days'  previous  notice 
in  writing  to  the  Company. 

28.  Except  with  the  written  consent   of  the   consumer,   no  cock, 
ferrule,   joint,   union,   valve,  or  other  fitting,  in   the  course   of  any 
"  communication  pipe,"  shall  have  a  water-way  of  less  area  than  that 
of  the  "communication  pipe,"  so  that  the  water-way  from  the  water 
in  the  district  pipe  or  other  supply  pipe  of  the  Company  up  to  and 
through  the  stop-valve  prescribed  by  Regulation  No.  12,  shall  not  in 
any  part  be  of  less  area  than  that  of   the   "  communication  pipe " 
itself,  which  pipe  shall  not  be  of  less  than  a  half-inch  bore  in  all  its 
courses. 

29.  All  lead  "warning  pipes"  and  other  lead  pipes  of  which  the 


446  WATER  SUPPLIES 

ends  are  open,  so  that  such  pipes  cannot  remain  charged  with  water, 
may  be  of  the  following  minimum  weights,  that  is  to  say  : — 

£  inch  (internal  diameter)      .         .         .         3  Ib.  per  yard. 

i  „  „  .     .     .     5ib. 

1     „  „  .         .         .         7lb.         „ 

30.  In  these  regulations  the  term  "  communication  pipe  "  shall  mean 
the  pipe  which  extends  from  the  district  pipe  or  other  supply  pipe  of 
the  Company  up  to  the  "  stop-valve "  prescribed  in  the  Regulation 
No.  12. 

31.  Every  person  who  shall  wilfully  violate,  refuse,  or  neglect  to 
comply  with,  or  shall  wilfully  do  or  cause  to  be  done  any  act,  matter, 
or  thing,  in  contravention  of  these  regulations,  or  any  part  thereof, 
shall,   for  every  such   offence,  be  liable  to  a  penalty  in  a  sum  not 
exceeding  £5. 

32.  Where,  under  the  foregoing  regulations,  any  act  is  required  or 
authorised  to  be  done  by  the  Company,  the  same  may  be  done  on 
behalf   of   the    Company   by   an  authorised  officer  or  servant  of  the 
Company,  and  where,  under  such  regulations,  any  notice  is  required  to 
be  given  by  the  Company,  the  same  shall  be  sufficiently  authenticated 
if  it  be  signed  by  an  authorised  officer  or  servant  of  the  Company. 

33.  All  existing  fittings,  which  shall  be  sound  and  efficient,  and  are 
not  required  to  be  moved  or  altered  under  these  regulations  shall  be 
deemed  to   be   "prescribed  fittings"   under  the   "Metropolis   Water 
Act,  1871." 

N.B. — Water  is  wasted  in  several  ways,  as  by  defective  works  and 
arrangements,  by  improper  fittings,  and  by  abuse  and  neglect ;  proper 
fittings,  and  sound  workmanship  will  give  good  works  a  fair  commence- 
ment, but  subsequent  inspection  and  repairs  will  be  necessary  so  long 
as  they  are  in  use.  It  will  be  found  by  experience  that  it  is  cheaper 
to  supervise  and  repair  the  mains  and  fittings,  rather  than  to  allow 
water  to  flow  to  waste. 


CHAPTER  XXIV. 

THE  LAW  KELATING  TO  WATER  SUPPLIES. 

IT  generally  happens  that  when  a  water  supply  is  to  be 
provided,  land  or  water  rights,  or  land  and  way  leaves, 
have  to  be  acquired.  This  may  be  done  either  voluntarily 
or  compulsorily,  the  Public  Health  Act,  1875,  section  175, 
providing  that  any  Local  Authority  may  purchase,  take  on 
lease,  sell,  or  exchange  any  lands,  whether  situated  within 
or  without  their  district,  and  may  also  buy  up  any  water- 
mill,  dam,  or  weir  which  interferes  with  the  proper 
drainage  of,  or  the  supply  of  water  to,  their  district.  It  is 
desirable,  if  possible,  to  purchase  voluntarily,  as  the 
expenses  of  acquiring  land  compulsorily  are  considerable, 
and  add  much  to  the  cost,  especially  in  the  case  of  village 
water  supplies.  But  it  frequently  happens  that  the 
necessary  land  can  only  be  acquired  by  compulsory  pur- 
chase, and  to  enable  Local  Authorities  to  purchase 
compulsorily,  the  Lands  Clauses  Consolidation  Acts  are,  by 
section  176  of  the  Public  Health  Act,  1875,  incorporated 
with  that  Act;  and  that  section  prescribes  the  course  to 
be  taken  by  a  Local  Authority  before  putting  in  force  the 
powers  of  the  Lands  Clauses  Acts  as  to  purchasing  and 
taking  lands  otherwise  than  by  agreement. 

The  Lands  Clauses  Act,  1845,  contains  valuable  powers, 
enabling  tenants  for  life  and  other  owners  of  limited 
estates  to  carry  out  voluntarily  sales  of  the  lands  in  which 
they  are  interested. 

Many  persons  being  incapacitated  from  selling  their 
lands  by  reason  of  disabilities  of  various  kinds,  section  6 

(447) 


448  WATER  SUPPLIES 

of  that  Act  enables  all  parties  entitled  to  any  such  lands, 
or  any  estate  or  interest  therein,  to  sell  and  convey  the 
same,  and  particularly  for  all  Corporations,  tenants  in  tail 
or  for  life,  married  women  seised  in  their  own  right  or 
entitled  to  dower,  Guardians,  Committees  of  Lunatics  and 
of  Idiots,  Trustees  or  Feoffees  in  trust  for  charitable  or 
other  purposes,  Executors  and  Administrators,  and  all 
parties  for  the  time  being  entitled  to  the  receipt  of  the 
rents  and  profits  of  any  lands  in  possession,  to  sell  the 
same. 

Similar  powers,  enabling  tenants  for  life  and  other 
persons  having  less  than  an  absolute  interest  in  lands  to 
sell  voluntarily,  are  conferred  by  the  Settled  Land  Act, 
1882,  under  sections  3  and  58  of  which  a  tenant  for  life, 
tenant  in  tail,  tenant  by  the  courtesy,  and  other  limited 
owners,  may  sell  the  settled  land  or  any  part  thereof,  or  any 
easement,  right,  or  privilege  of  any  kind  for  or  in  relation 
to  the  land. 

There  is  a  prevalent  idea  that  Local  Authorities  may  use 
roadsides  wastes  for  sinking  wells  and  other  water  supply 
purposes ;  but  this  is  erroneous.  Local  Authorities,  as 
such,  have  no>  rights  whatever  in  these  wastes,  and  the 
law  presumes,  until  evidence  is  given  to  the  contrary,  that 
the  soil  of  the  roadway  to  the  middle  of  the  road,  and  of 
the  adjoining  strip  of  waste  belongs  to  the  owner 
of  the  land  adjoining  to  the  highway  or  to  the  strip 
of  waste ;  and  the  owner  of  the  roadway  and  of 
the  strip  of  waste  is  entitled  to  use  his  property 
in  every  way  not  inconsistent  with  the  public  right  of 
passage,  the  right  of  the  public  merely  extending  to  pass 
along  the  surface  of  the  road,  and  for  that  purpose  to 
keep  it  in  repair. 

This  presumption  as  to  the  ownership  of  the  soil  of  the 
roadway  has  been  said  to  rest  on  the  supposition  that  when 
the  road  was  originally  set  out,  the  proprietors  of  the 
adjoining  land  each  contributed  a  portion  of  their  land 


THE  LAW  RELATING  TO  WATER  SUPPLIES         44§ 

for  its  formation,  and  the  presumption  that  the  soil  of  a 
strip  of  land  lying  between  the  highway  and  the  adjacent 
enclosure  belongs  to  the  owner  of  that  enclosure  is  founded 
on  the  supposition  that  the  proprietor  of  the  adjoining 
land,  at  some  former  period,  gave  up  to  the  public  free 
passage  of  the  land  between  his  enclosure  and  the  middle 
of  the  road,  or,  when  enclosing  his  land  for  the  road,  he 
left  an  open  space  at  the  side  of  the  road,  over  which  the 
public  might  deviate  if  necessary,  to  avoid  the  liability 
to  repair  which  would  otherwise  have  fallen  upon  him.  If 
the  strip  of  land  communicates  with  or  is  contiguous  to  an 
open  common  or  large  portion  of  land,  the  presumption,  is 
done  away  with  or  considerably  narrowed,  for  the  evidence 
of  ownership  which  applies  to  the  large  portions  applies 
also  to  the  narrow  strip  which  communicates  with  them. 

Before  proceeding  to  purchase  lands,  springs,  or  streams 
for  water-supply  purposes,  precautions  should  be  taken — 

(a)  To  ascertain  whether  and  to  what  extent  neighbour- 

ing landowners  can  prevent,  by  legal  proceedings, 
the  water  yielded  therefrom  being  used  for  the 
proposed  water-supply  purposes. 

(b)  Whether  and  to  what  extent  such  landowners  can, 

by  digging  wells,  cutting  trenches,  or  executing 
other  works  on  their  o>wn  lands,  abstract  or  divert 
the  water  proposed  to  be  utilised. 

As  to  the  first  question — As  a  general  rule  every  land- 
owner (including  a  Local  Authority  owning  land)  has  the 
right  to  dig  wells  and  execute  other  works  on  his  land,  and 
thus  obtain  or  divert  for  his  own  purposes  as  much  of  the 
water  flowing  under  his  land  as  he  can,  even  though 
the  effect  may  be  to  abstract  or  divert  the  underground 
waters  which  otherwise  would  flow  to  and  become  feeders 
of  springs  and  streams  on  other  property.  But  the  law  is 
different  with  regard  to  a  watercourse,  which  has  been 
defined  by  Lord  Tenterden  as  "  water  flowing  in  a  channel 
between  banks  more  or  less  defined." 

29 


450  WATER  SUPPLIES 

The  riparian  proprietors  whose  lands  adjoin  a  water- 
course may  take  water  from  it,  but  in  doing  so  must  have 
due  regard  to  the  similar  rights  of  others  whose  lands 
adjoin  the  stream,  and  who  have  the  right  "  to>  have  the 
watercourse  or  stream  come  to>  them  in  its  natural  state  in 
flow,  quality,  and  quantity." 

A  spring  and  a  stream  have  been  thus  denned  by  Jessel, 
M.R. — "  A  spring  of  water  is,  as  I  understand  it,  a  natural 
source  of  water,  of  a  definite  and  well-marked  extent.  A 
stream  of  water  is  water  which  runs  in  a  defined  course, 
so  as  to  be  capable  of  diversion,  and  it  has  been  held  that 
the  term  does  not  include  the  percolation  of  underground 
water."  What  is  a  stream,  and  where  does  it  begin?  is  a 
question  which  was  raised  in  the  case  of  Dudden  v. 
Guardians  of  the  Glutton  Union,  reported  in  11  Exchequer 
Reports,  627,  and  26  Law  Journal  Reports,  Exchequer, 
146,  where  the  plaintiff  was  the  owner  of  an  ancient  mill 
which  was  supplied  with  water  from  a  brook.  Adjoining 
this  brook  was  a  spring,  the  water  from  which  flowed  by  a 
natural  channel  into  the  brook.  The  guardians,  for  the 
purpose  of  supplying  the  workhouse  with  water,  placed 
tanks  and  pipes  close  to  the  spring-head,  and  took  the 
water  before  it  flowed  into  the  natural  channel.  The 
judge  directed  the  jury  to  find  for  the  plaintiff  (and  they 
did  so)  if  they  thought  the  water  flowed  in  a  defined 
regular  course  from  the  spring-head  to  the  brook. 

Upon  the  application  to  the  Court  to  set  aside  the 
verdict,  Baron  Martin  thus  stated  the  law: — "  The  right 
to  flowing  water  is  a  natural  right,  and  all  parties  are 
entitled  to  the  use  of  it,  but  a  party  would  not  be  entitled 
to  divert  it  when  it  is  in  the  act  of  springing  from  the 
ground.  He  cannot  legally  prevent  its  flowing  into  its 
natural  channel."  And  Baron  Watson  added,  "  If  the 
diversion  in  this  case  had  taken  place  ten  yards  from  the 
spring-head,  there  would  be  no  doubt  in  the  case,  and  the 
rule  is  the  same  if  the  water  is  diverted  at  the  source." 


THE  LAW  RELATING  TO  WATER  SUPPLIES         451 

The  law  respecting  the  right  to  water  flowing  in  definite 
visible  channels  is  clearly  enunciated  by  the  judgment  of 
the  Court  of  Exchequer  in  the  case  of  Embrey  v.  Owen, 
reported  in  6  Exchequer  Reports,  353,  and  20  Law  Journal 
Reports,  E.  212. 

This  case  decided  that  water  is  publici  juris  in  this  sense 
only,  that  all  may  reasonably  use  it  who  have  the  right  of 
access  to  it.  No  man  can  have  any  property  in  the  water 
itself,  except  in  that  particular  portion  which  he  may 
choose  to  abstract  from  the  stream  and  take  into  his  own 
possession,  and  that  during  the  time  of  his  possession  only. 
Also  that  the  proprietor  of  the  adjacent  land  has  the  right 
to  the  usufruct  of  the  streams  that  flow  through  it,  not  as 
an  absolute  and  exclusive  right  to  the  flow  of  all  the  water 
in  its  natural  state,  but  subject  to  the  similar  rights  of  all 
proprietors  of  the  banks  on  each  side  to  a  reasonable 
enjoyment  thereof. 

In  the  case  of  Milner  v.  Gilmour,  Lord  Kingsdown  laid 
down,  the  law  as  to  running  streams  as  follows: — "  By  the 
general  law  applicable  to  a  running  stream,  every  riparian 
proprietor  has  a  right  to  what  may  be  called  the  ordinary 
use  of  the  water  flowing  past  his  land,  for  instance  to  the 
reasonable  use  of  the  water  for  his  domestic  purposes  and 
for  his  cattle,  and  this  without  regard  to  the  effect  which 
such  use  may  have  in  case  of  deficiency  upon  proprietors 
lower  down  the  stream ;  but  further  he  has  a  right  to  the 
use  of  it  for  any  purpose,  or  what  may  be  termed  the 
extraordinary  use  of  it,  provided  that  he  does  not  thereby 
interfere  with  the  rights  of  other  proprietors  either  above 
or  below  him.  Subject  to  this  condition  he  may  dam  it 
for  the  purposes  of  a  mill,  or  divert  the  water  for  the 
purpose  of  irrigation,  but  he  has  no  right  to  interrupt  the 
regular  flow  of  the  stream  if  he  thereby  interferes  with  the 
lawful  use  of  the  water  by  other  proprietors,  and  inflicts 
upon  them  a  sensible  injury."  Such  extraordinary  use,  in 
order  to  be  justifiable,  must,  however,  be  a  reasonable  one, 


452  WATER  SUPPLIES 

and  one  for  which  a  riparian  proprietor  is  entitled  to  take 
the  water  from  its  natural  course;  for  where  an  unreason- 
able use  is  made  of  the  water  by  one  riparian  proprietor, 
the  others  are  entitled  to  have  it  restrained,  even  though 
they  prove  no  actual  damage,  on  the  ground  that  it  is  an 
interference  with  a  right  which,  unless  restrained,  would 
in  the  course  of  twenty  years  confer  on  the  claimant  a 
right  of  prescription  in  derogation  of  the  prior  right.  It 
would  appear  from  the  case  of  the  Swindon  Water  Co. 
v.  Wilts  and  Berks  Canal  (Law  Reports,  9  Ch.  457),  that 
an  "  extraordinary  use,"  as  well  as  being  reasonable,  must 
be  for  the  use  of  the  riparian  tenement. 

But  the  law  as  laid  down  in  these  cases  is  inapplicable  to 
the  case  of  subterranean  water  not  flowing  in  any  separate 
channel,  or  flowing  indeed  at  all  in  the  ordinary  sense, 
but  percolating  or  oozing  through  the  soil,  more  or  less 
according  to  the  quantity  of  rain  that  may  chance  to  fall. 

The  case  of  Broadbent  v.  Ramsbotham,  reported  in  11 
Exchequer  Reports,  611,  and  26  Law  Journal  Reports,  Ex. 
115,  decided  that  the  right  of  a  riparian  owner  to  the 
lateral  tributaries  or  feeders  of  the  main  stream  applies  to 
waters  flowing  in  a  denned  and  natural  channel  or  water- 
course, and  does  not  extend  to  water  flowing  over,  or 
soaking  through,  previous  to  its  arrival  at  such  water- 
course. 

In  this  case  it  was  decided  that  the  plaintiff,  who  was  a 
millowner,  having  the  right  to  use  the  water  of  a  natural 
stream,  called  Longwood  brook,  had  no  cause  of  action 
against  the  owners  of  adjacent  land  for  diverting  water, 
which,  coming  from  a  pond  formed  by  landslips,  escaped 
over  the  surface  of  this  land,  and  thence,  by  natural  force 
of  gravity,  found  its  way  by  land-drains  or  dykes  to  the 
brook ;  or  for  diverting  the  overflow  from  a  well  and  a 
swamp  on  that  land,  which  ran  in  wet  seasons  to  the  brook ; 
or  for  diverting  the  overflow  from  another  well  on  that 
land  used  as  a  watering-place  for  cattle,  which  overflow 


THE  LAW  RELATING  TO  WATER  SUPPLIES         453 

formed  a  stream,  and,  after  following  the  course  of  an 
artificial  ditch,  along  a  hedge-side,  and  in  other  parts 
flowing  down  a  small  channel,  formed  by  the  water,  and  over 
swampy  places,  where  the  cattle  had  trodden  in  the  soil, 
ran  over  a  field,  and  thence  along  a  natural  valley,  and 
along  hedge-sides  and  ditches,  and  discharged  itself  into 
the  brook;  and  it  was  held  that  the  plaintiff,  although  he 
had  a  right  to  the  use  of  the  water  of  the  brook,  had  no 
cause  of  action  against  the  owner  of  the  adjacent  land  for 
diverting  either  of  the  above  three  sources  of  supply  before 
the  waters  had  arrived  at  a  definite  natural  watercourse. 

With  regard  to  the  second  question,  the  law  has  been 
defined  and  settled  by  two  important  decisions  of  the  House 
of  Lords,  the  first  of  Chasemore  v.  Richards,  decided  in 
July,  1859,  and  reported  in  7  House  of  Lords  Reports,  382, 
and  29  Law  Journal  Reports,  Exchequer,  81,  which  decided 
that  the  owner  of  land,  containing  underground  water 
which  percolates  by  undefined  channels,  and  flows  to  the 
land  of  a  neighbour,  has  the  right  to  divert  or  appropriate 
the  percolating  water  within  his  own  land,  so  as  to  deprive 
his  neighbour  of  it. 

In  that  case,  much  of  the  law  relating  to  waters  flowing 
above  or  underground  was  dealt  with  by  the  various  learned 
judges  who  delivered  judgments.  The  facts  of  the  case  and 
the  law  relating  to  it  were  stated  by  Mr.  Justice  Wightman 
as  follows :  — 

"  The  plaintiff  is  the  occupier  of  an  ancient  mill  on  the 
river  Wandle,  and  for  more  than  sixty  years  he  and  his 
predecessors  had  used  and  enjoyed,  as  of  right,  the  flow  of 
the  river  for  the  purposes  of  working  their  mill ;  the  river 
had  always  been  supplied  above  the  plaintiff's  mill,  in  part, 
by  the  water  produced  by  the  rainfall  on  a  district  of  many 
thousand  acres  in  extent,  comprising  the  town  of  Croydon 
and  its  vicinity.  The  water  of  the  rainfall  sinks  into  the 
ground  to  various  depths,  and  then  flows  and  percolates 
through  the  strata  to  the  river  Wandle,  part  rising  to  the 


454  WATER  SUPPLIES 

surface,  and  part  finding  its  way  underground  in  courses 
which  continually  vary. 

"  The  Croydon  Loical  Board  sink  a  well  in  their  own 
land  in  the  town  of  Croydon,  and  by  means  of  the  well  and 
by  pumping  from  it  large  quantities  of  water  for  the  supply 
of  the  town  of  Croydon,  the  Board  abstracted  and  inter- 
rupted underground  water  (but  underground  water  only) 
that  otherwise  would  have  flowed  and  found  its  way  into 
the  river  Wandle,  and  so  to  the  plaintiff's  mill,  and  the 
quantity  so  diverted  was  sufficient  to  be  of  sensible  value 
toward  working  the  mill." 

The  law  as  decided  in  Chasemore  v.  Richards  has  been 
followed  and  extended  by  the  important  recent  case,  decided 
by  the  House  of  Lords  in  July,  1895,  of  the  Mayor, 
Aldermen,  and  Burgesses  of  the  Borough  of  Bradford  v. 
Edward  Pickles,  where  it  was  decided  that  not  only  has  the 
owner  of  land  containing  underground  water  which  per- 
colates by  undefined  channels  and  flows  to  the  land  of  his 
neighbour  the  right  to  divert  or  appropriate  the  percolating 
water  within  his  own  land  so  as  to  deprive  his  neighbour 
of  it,  but  his  right  to  do  this  is  the  same  whatever  his 
motive  may  be,  whether  to  improve  his  own  land  or 
maliciously  to  injure  his  neighbour  or  to  induce  his 
neighbour  to  buy  him  out.  In  this  case  the  Corporation  of 
Bradford  were  the  owners  of  Trooper  Farm  and  certain 
springs  and  streams  rising  in  or  flowing  through  that  farm, 
which  were  purchased  many  years  ago>  by  the  Bradford 
Waterworks  Company,  and  from  which  the  Corporation 
obtained  a  valuable  supply  of  water  for  the  domestic  use 
of  the  inhabitants  of  Bradford.  In  1892  the  respondent 
Pickles  began  to  sink  a  shaft  on  his  land  adjoining  Trooper 
Farm,  and  also  to  drive  a  level  through  his  land  for  the 
professed  purpose  of  draining  the  strata  with  the  view  to 
the  working  of  his  minerals.  These  operations  had  the 
effect  of  diminishing  the  water  supply  obtainable  from  the 
springs  on  Trooper  Farm.  The  Corporation  of  Bradford 


THE  LAW  RELATING  TO  WATER  SUPPLIES         455 

brought  this  action  to  restrain  the  defendant  Pickles  from 
continuing  to  sink  the  shaft  or  drive  the  level,  and  from 
doing  anything  whereby  the  waters  of  the  spring  and  the 
stream  might  be  drained  off  or  diminished  in  quantity. 
Lord  Halsbury,  in  delivering  judgment,  said :  "  The  acts 
done  or  said  to  be  done  by  the  defendant  werei  all  done 
upon  his  own  land,  and  the  interference,  whatever  it  is, 
with  the  flow  of  water  is  an  interference  with  water 
which  is  underground  and  not  shown  to  be  water 
flowing  in  any  defined  stream,  but  is  percolating  water 
which,  but  for  such  interference,  would  undoubtedly 
reach  the  plaintiffs'  waterworks,  and  in  that  sense  it  has 
deprived  them  of  the  water  which  they  would  otherwise 
get ;  but  although  it  has  deprived  them  of  water  which  they 
would  otherwise  get,  it  is  necessary  for  the  plaintiffs  to 
establish  that  they  have  a  right  to  the  flow  of  water,  and 
that  the  defendant  has  no  right  to  do  what  he  is  doing. 
I  am  of  opinion  that  the  question  whether  the  plaintiffs 
have  a  right  to  the  flow  of. such  water  is  covered  by  the 
decision  in  the  case  of  Chasemore  v.  Richards.  The  very 
question  was  then  determined  by  this  House,  and  it  was 
held  that  the  landowner  has  a  right  to  do  what  he  had  done, 
whatever  his  object  or  purpose  might  be,  and  although  the 
purpose  might  be  wholly  unconnected  with  the  enjoyment 
of  his  own  estate." 

In  delivering  his  judgment,  Lord  Macnaughten  stated : 
"  The  position  of  the  appellants  is  one  which  it  is  not  easy 
to  understand.  They  cannot  dispute  the  law  laid  down  by 
this  House  in  Chasemore  v.  Richards.  They  do  not  suggest 
that  the  underground  water  with  which  Mr.  Pickles 
proposes  to  deal  flows  in  any  defined  channel.  But  they 
say  that  Mr.  Pickles'  action  in  the  matter  is  malicious,  and 
that,  because  his  motive  is  a  bad  one,  he  is  not  at  liberty  to 
do  a  thing  which  every  landowner  may  do  with  impunity 
if  his  motives  are  good.  It  may  be  taken  that  his  real 
object  was  to  show  that  he  was  the  master  of  the  situation, 


456  WATER  SUPPLIES 

and  to  force  the  Corporation  to  buy  him  out  at  a  price 
satisfactory  to  himself.  Well,  he  has  something  to  sell,  or, 
at  any  rate,  he  has  something  which  he  can  prevent  other 
people  enjoying  without  paying  for  it.  Why  should  he, 
he  may  think,  without  fee  or  reward,  keep  his  land  as  a 
storeroom  for  a  commodity  which  the  Corporation  dispense, 
probably  not  gratuitously,  to  the  inhabitants  of  Bradford? 
He  prefers  his  own  interests  to  the  public  good.  He  may 
be  churlish,  selfish,  and  grasping.  But  where  is  the 
impulse?  Mr.  Pickles  has  no>  spite  against  the  people  of 
Bradford.  He  bears  no  ill-will  to  the  Corporation.  They 
are  welcome  to  the  water,  and  to  his  land  too,  if  they  will 
pay  the  price  for  it.  So  much,  perhaps,  might  be  said  in 
defence,  or  in  palliation  of  Mr.  Pickles'  conduct,  but  the 
real  answer  to  the  claim  of  the  Corporation  is  that  in  such 
a  case  motives  are  immaterial.  It  is  the  act,  not  the  motive 
for  the  act,  that  must  be  regarded.  If  the  act,  apart  from 
the  motive,  gives  rise  merely  to  damage  without  legal 
injury,  the  motive,  however  reprehensible  it  may  be,  will 
not  apply  without  element." 

Since  the  last  edition  of  this  book  was  written  a  further 
interesting  case  on  the  rights  to  underground  water  has 
arisen  and  been  decided  by  the  Court  of  Appeal.  The 
case  is  reported  in  the  Law  Reports,  1899,  2  Chan.,  p.  217, 
Jordeson  v.  Sutton,  Southcoates  and  Dryport  Gas  Com- 
pany. The  head  note  to  the  case  is  as  follows :  "  The 
plaintiff  was  the  owner  of  land  with  houses  on  it,  and  the 
adjoining  land  belonged  to  the  defendants,  a  Gas  Company, 
incorporated  by  special  Act,  with  power  to  purchase  land 
by  agreement  only,  and  subject  to  the  provisions  of  the 
Gas  Works  Clauses  Acts,  1847  an|d  1871.  The  Company 
proceeded  to  excavate  their  land  for  the  purpose  of  erect- 
ing a  gasometer.  In  so  doing  they  penetrated  an  under- 
ground stratum  of  quicksand,  or  sand  loaded  with  water, 
geologically  know  as  '  running  silt/  which  extended  under 
the  plaintiff's  land  as  well  as  their  own,  the  land  largely 


THE  LAW  RELATING  TO  WATER  SUPPLIES         457 

preponderating  over  the  water.  In  draining  their  exca- 
vation the  defendants  withdrew  a  large  quantity  of  the 
running  silt  from  under  the  plaintiff's  land,  and  thus 
caused  a  subsidence  of  the  surface  with  consequent  struc- 
tural injury  to  his  houses.  It  was  held  by  the  Court  of 
Appeal  (Lindley,  M.R.,  and  Rigby,  L.J.)  that  the  plain- 
tiff's land  was  supported,  not  by  a  stratum  of  water  but 
by  a  bed  of  wet  sand  or  running  silt;  and  that  as  the 
defendants  had  caused  the  subsidence  by  withdrawing  this 
support  they  had  committed  an  actionable  nuisance  at 
Common  Law,  entitling  the  plaintiff  to  damages ;  but 
Yaughan-Williams,  L.J.,  held  that  the  subsidence  had  been 
caused  by  the  withdrawal  through  the  defendants  draining 
operations  on  their  own  land  of  subterranean  water  sup- 
port of  the  plaintiff's  land,  and  that  on  the  authority  of 
Popplewell  v.  Hodkinson,  L.R.  4  Ex.  288,  the  withdrawal 
of  subterranean  water  support  from  a  neighbour's  land  in 
the  course  of  draining  one's  own  land  gives  him  no>  cause 
of  action." 

So,  as  the  law  now  stands  (the  decision  of  the  majority  of 
the  Court  of  Appeal  standing)  in  any  draining  or  drawing 
of  water  operations,  care  must  be  taken  to  draw  nothing 
but  water,  or  at  all  events  only  to  a  small  extent,  for  if  any 
quantity  of  silt  or  sand  is  drawn  with  the  water  and  damage 
is  sustained,  the  withdrawer  of  the  water  will  be  liable  for 
such  damage ;  'but  if  only  water  is  drawn,  then,  though  he 
may  do  a  considerable  amount  of  damage,  until  this  de- 
cision is  in  effect  reversed  by  a  decision  of  the  House  of 
Lords,  or  until  some  Act  of  Parliament  is  passed  further 
denning  the  rights  to  underground  water,  he  cannot  be 
mulct  in  damages. 

Popplewell  v.  Hodkinson,  whioh  was  a  case  of  appeal 
from  the  old  Court  of  Exchequer,  held  that  an  owner  of 
land  has  no  right  at  Common  Law  to  the  support  of  sub- 
terranean water. 

The  law  as  to  the  making  and  recovery  of  water-rates 


458  WATER  SUPPLIES 

and  water-rents  is  much  in  need  of  consolidation  and 
amendment.  The  Waterworks  Clauses  Act,  1863,  and 
certain  provisions  of  the  Waterworks  Clauses  Act,  1847, 
are  incorporated  with  the  Public  Health  Act,  1875,  and  the 
following  clauses  of  the  1847  Act  may  be  referred  to,  as  to 
water-rates  and  water-rents  :  — 

"  Sees.  48  to  52.  Any  owner  or  occupier  of  a  dwelling- 
house  may  open  ground,  and  lay  communication  or  service 
pipes  to  connect  house  with  mains,  under  certain  conditions. 

"  Sec.  53.  Every  owner  and  occupier,  when  he  has  laid 
such  communication  pipes  and  paid  the  water-rate,  is 
entitled  to  a  sufficient  supply  of  water  for  domestic 
purposes. 

"  Sec.  68.  Water-rates  (except  as  in  sec.  72)  are  to  be 
paid  by  the  person  receiving  or  using  the  supply  of  water, 
and  to  be  payable  according  to*  the  annual  value  of  the 
tenement  supplied,  any  dispute  arising  as  to  such  value 
to  be  settled  by  two  justices. 

"  Sec.  69.  When  several  houses,  or  parts  of  houses  in  the 
separate  occupations  of  several  persons,  are  supplied  by  one 
common  pipe,  the  several  owners  or  occupiers  are  liable  to 
the  payment  of  the  same  water-rates  as  if  each  were 
supplied  by  a  separate  pipe. 

"  Sec.  70.  Water-rates  to  be  paid  in  advance,  by  equal 
quarterly  payments,  at  Christmas  Day,  Lady  Day,  Mid- 
summer Day,  and  Michaelmas  Day. 

"  Sec.  72.  The  owners  of  all  dwelling-houses  or  separate 
tenements,  the  annual  value  of  which  does  not  exceed  <£10, 
are  liable  to  payment  of  .the  water-rates  instead  of  the 
occupiers." 

To  make  the  owner  or  occupier  liable,  it  is  not  necessary 
that  the  water  should  be  laid  on  to  the  house,  section  9  of 
the  Public  Health  Water  Act,  1878,  enacting  that  where 
a  stand  pipe  has  been  provided  water-rates  or  water-rents 
may  be  recovered  from  the  owner  or  occupier  of  every 
dwelling-house  within  200  feet  of  any  such  stand  pipe, 


THE  LAW  RELATING  TO  WATER  SUPPLIES         459 

in  the  same  manner  as  if  the  supply  had  been  given  on  the 
premises.  But  if  such  dwelling-house  has  within  a  reason- 
able distance,  and  from  other  sources,  a  supply  of  wholesome 
water  sufficient  for  the  consumption  and  iise  of  the  inmates, 
no  water-rate  or  water-rent  is  recoverable  from  the  owner 
or  occupier  until  the  water  supplied  from  the  stand  pipes 
is  used  by  the  inmates  of  the  house.  This  section  applies 
to  rural  districts  only. 

Where  stand  pipes  are  used  questions  are  often  raised 
by  householders,  who  seem  to  object  to  water-rates,  even 
more  than  to  other  rates,  on  the  ground  that  their  houses 
are  provided  with  water  from  some  ancient  well,  or  other 
source.  A  little  patience  is  generally  not  wasted  on  them, 
for  if  left  alone  they  soon  find  the  use  of  the  water  from 
the  stand  pipe  to  be  so  great  a  convenience  that  they  take 
to  using  it,  and  then  pay  the  water-rates  with  as  good 
grace  as  they  do  other  rates.  In  some  cases,  however, 
where  a  water-rate  hater  insists  on  continuing  to  use  water 
from  some  polluted  well  or  other  source,  it  becomes 
necessary  to  compel  him  to  pay  the  water-rate,  even  though 
he  does  not  use  the  water  from  the  stand  pipe,  on  the 
ground  that  his  supply  is  not  wholesome.  When  compelled 
to  pay  the  rate  he  will  soon  begin  to  us©  the  water,  to  get 
over  his  objection  to  being  made  to  pay  for  what  he  does 
not  use. 

"  Sec.  74.  If  a  person  liable  to  pay  water-rates  neglects 
to  do  so,  water  may  be  cut  off,  and  water-rates  and  expenses 
of  cutting  off  the  water  recovered  in  manner  mentioned  in 
the  section." 

Objection  is  often  made  that  the  incidence  of  a  water-rate 
is  unfair,  because,  assuming  the  water-rate  to  be  Is.  in  the 
£1,  one  occupier  of  a  house  rated  at,  say,  £15,  and  using 
very  little  water,  pays  as  much  for  his  water-rate  as  another 
neighbouring  occupier  of  a  similarly-rated  house,  or  house 
and  shop,  possibly  using  many  times  as  much  water  as  his 
neighbour.  This  may  be  often  so,  for  the  quantity  used 


460  WATER  SUPPLIES 

will  depend  on  the  number  and  habits  of  the  household, 
and  whether  baths  and  water-closets  are  used  or  not ;  but 
section  12  of  the  Waterworks  Clauses  Act,  1863,  provides 
that  a  supply  of  water  for  domestic  purposes  is  not  to 
include  a  supply  of  water  for  cattle  or  for  horses,  or  for 
washing  carriages,  where  kept  for  sale  or  hire,  or  by  a 
common  carrier,  or  a  supply  for  any  trade,  manufacture, 
or  business,  or  for  watering  gardens,  or  for  fountains,  or 
for  any  ornamental  purpose. 

Where  water  is  used  for  flushing  sewers,  road  watering, 
etc.,  a  charge  should  be  made  on  the  general  district  rate 
for  the  water  so  used.  In  some  districts  the  rates  paid 
by  the  users  of  the  water  cover  not  only  the  annual 
repayment  of  the  loan,  with  interest,  but  also  the  cost  of 
maintenance.  In  this  case  the  tenants  or  owners  of  the 
property  pay  for  the  waterworks  in  the  course  of  a  term 
of  years,  at  the  end  of  which  they  are  the  absolute 
property  of  the  L.A.,  and  not  of  those  who  have  paid  for 
them.  In  other  cases  the  water-rates  only  cover  the 
interest  and  cost  of  maintenance,  the  principal  being  paid 
off  from  the  general  district  rate.  This  seems  a  perfectly 
fair  arrangement,  as  the  works  ultimately  become  the 
property  of  the  L.A.,  which  has  paid  for  them.  In  other 
instances  the  sum  to  be  paid  by  the  users  of  the  water  is 
fixed  in  an  arbitrary  manner,  and  the  balance  raised  from 
the  general  district  rate.  The  mode  in  which  the  cost  of 
public  supplies  is  met,  in  different  districts,  is  referred 
to  in  the  subjoined  chapter  on  rural  water  supplies. 

Up  to  the  passing  of  the  Local  Government  Act,  1894, 
the  Rural  Sanitary  Authority  was,  under  the  Public 
Health  Act,  1875,  the  only  body  having  power  to  provide 
water-supply  works  in  rural  parishes;  but  under  section  8 
of  the  1894  Act  a  Parish  Council  has  power  to  utilise  any 
well,  spring,  or  stream,  within  their  parish,  and  provide 
facilities  for  obtaining  water  therefrom,  but  so  as  not  to 
interfere  with  the  rights  of  any  corporation  or  person ; 


THE  LAW  RELATING  TO  WATER  SUPPLIES         461 

and  the  Parish  Council  have  power  also*  under  the  same 
section  to  contribute  towards  the  expense  of  doing  this, 
or  to  concur  or  combine  with  any  other  Parish  Council 
to  do  so,  or  contribute  towards  the  expense  of  such  water 
supply.  It  is  probable  that  these  powers  will  be  seldom 
used,  because  the  Rural  District  Councils  have  already 
full  power  to  provide  water  supplies  for  any  parish  in 
their  districts,  the  expense  of  so  doing  being  a  special 
charge  upon  that  parish ;  and  it  is  provided  in  section  8 
that  nothing  contained  in  that  section  shall  derogate  from 
the  obligation  of  the  District  Council  with  respect  to  the 
supply  of  water;  also  that  Parish  Councils  are  not  to 
acquire,  otherwise  than  by  agreement,  any  land  for  the 
purpose  of  any  water  supply.  The  1894  Act,  however, 
contains  useful  provisions  for  the  protection  of  these 
councils,  with  regard  to  the  action  of  the  Rural  District 
Councils  as  to  water  supply,  section  16  providing  that 
where  the  Rural  District  Council  has  determined  to  adopt 
plans  for  the  water  supply  of  any  parish,  it  shall  give 
notice  thereof  to  the  Parish  Council  of  the  parish  for 
which  the  works  are  to  be  provided,  before  any  contract 
is  entered  into  for  carrying  out  the  works.  Also  that 
where  a  Parish  Council  has  resolved  that  a  Rural  District 
Council  ought  to  have  provided  the  parish  with  a  supply 
of  water,  in  case  where  danger  arises  to  the  health  of 
the  inhabitants  from  the  insufficiency  or  unwholesomeness 
of  the  supply  of  water,  and  a  proper  supply  can  be 
obtained  at  a  reasonable  cost,  the  Parish  Council  may 
complain  to  the  County  Council,  who>,  if  satisfied  that  the 
District  Council  has  so  failed,  may  resolve  that  the  duties 
and  powers  of  the  District  Council,  for  the  purpose  of 
the  matter  complained  of,  shall  be  transferred  to  the 
County  Council,  and  they  shall  be  transferred  accordingly; 
or  instead  thereof  may  make  a  similar  order  to  that 
mentioned  in  section  299  of  the  Public  Health  Act,  1875, 
and  appoint  a  person  to  perform  the  duty  of  providing 
the  district  with  a  water  supply. 


462  WATER  SUPPLIES 

Before  giving  details  of  schemes  which  have  been 
selected  as  typical,  it  may  be  well  to  mention  categorically 
the  more  important  clauses  of  certain  Acts  of  Parliament 
bearing  upon  the  provision  of  water  supplies  by  Sanitary 
Authorities,  some  of  which  have  already  been  referred  to. 

The  Acts  more  particularly  applying  to  water  supplies 
are,  the  Public  Health  Act,  1875,  clauses  51  to  70  in- 
clusive; and  the  Public  Health  (Water)  Act,  1878.  In 
the  following  paragraphs  the  former  will  be  referred  te- 
as the  P.H.A.,  and  the  latter  as  the  P.H.W.A. ;  the 
No.  of  the  section  will  be  placed  in  brackets,  and  L.A. 
will  signify  the  Local  Sanitary  Authority. 

P.H.A.  (64).  By  this  clause  all  existing  public  cisterns, 
pumps,  wells,  reservoirs,  conduits,  aqueducts,  and  works 
are  vested  in  and  under  the  control  of  the  L.A. 

Where  a  spring  or  other  source  of  water  is  vested  in  the 
L.A.,  and  can  be  utilised  for  a  public  supply,  there  are 
no  water  rights  to  purchase. 

P.H.A.  (51).  The  L.A.  may  provide  their  district,  or 
any  portion  of  their  district,  with  a  supply  of  water,  and 
for  this  purpose  may  (a)  construct  waterworks,  dig  wells, 
etc. ;  (b)  lease,  or  hire,  or  purchase  waterworks ;  or  (c) 
contract  with  any  person  for  a  supply  of  water. 

P.H.A.  (54).  The  L.A.  have  the  same  powers,  etc.,  for 
carrying  water  mains  as  they  have  for  carrying  sewers. 

P.H.A.  (299-301).  If  a  L.A.  neglects  to  supply  any 
portion  of  its  district  with  wholesome  water,  where  the 
present  supply  is  a  danger  to  health  on  account  of  its 
insufficiency  or  unwholesomeness,  and  a  proper  supply 
can  be  obtained  at  a  reasonable  cost,  complaint  may  be 
made-  to  the  Local  Government  Board  by  any,  person, 
and  the  Local  Government  Board  may  order  the  L.A.  to 
provide  a  supply. 

P.H.A.  (56  and  58).  The  L.A.  may  charge  water-rates, 
or  supply  the  water  by  meter,  or  may  make  special  agree- 
ments with  the  person  receiving  the  supply. 


THE  LAW  RELATING  TO  WATER  SUPPLIES         463 

P.H.A.  (61).  Any  L.A.  may  supply  water  to  an  adjoin- 
ing district,  with  the  consent  of  the  Local  Government 
Board. 

P.H.A.  (62).  Where  the  Surveyor  to  the  L.A.  reports 
that  any  house  within  the  district  is  without  a  proper 
supply  of  water,  and  that  a  supply  can  be  had  at  a 
reasonable  cost,  the  L.A.  may  compel  the  owner  to  provide 
a  supply.  If  he  makes  default  the  L.A.  may  execute  the 
works,  and  either  recover  the  expenses  in  a  summary 
manner,  or  may  levy  a  rate  on  the  premises. 

P.H.A.  (70).  The  L.A.  may  apply  to  a  court  of 
summary  jurisdiction  for  an  order  to  close  any  well,  tank, 
or  cistern,  public  or  private,  which  is  reported  to  be  so 
polluted  as  to  be  injurious  to  health. 

P.H.W.A.  (3).  It  is  the  duty  of  every  Rural  Sanitary 
Authority  to  see  that  every  occupied  dwelling-house  has 
a  proper  supply  of  water.  A  portion  of  this  clause 
resembles  that  of  the  P.H.A.  (62),  but  is  less  ambiguous 
in  its  wording,  and  the  Medical  Officer  of  Health  or 
Sanitary  Inspector  is  empowered  to  report,  and  not  the 
Surveyor.  By  a  reasonable  cost  is  meant  a  sum  of 
.£8  13s.  4d.,  the  interest  of  which,  at  5  per  cent,  per 
annum,  is  2d.  per  week ;  or,  on  the  application  of  the  L.A., 
such  other  cost  not  exceeding  a  capital  sum  (£13),  the 
interest  on  which,  at  the  rate  of  5  per  cent,  per  annum, 
would  amount  to  3d.  per  week.  The  owner  may  object 
on  various  grounds,  one  of  which  is  that  the  L.A.  ought 
themselves  to  provide  a  supply  of  water  for  the  district, 
or  the  portion  thereof  in  which  the  house  is  situated. 

P.H.W.A.  (6).  No  new  house  shall  be  inhabited  until 
a  certificate  has  been  obtained  from  the  L.A.  to  the  effect 
that  it  has,  "  within  a  reasonable  distance,  such  an 
available  supply  of  wholesome  water  as  may  appear  to 
such  Authority,  on  the  report  of  their  Inspector  of 
Nuisances  or  of  their  Medical  Officer  of  Health,  to  be 


464  WATER  SUPPLIES 

sufficient    for     the    consumption     and     use    for     domestic 
purposes  of  the  inmates  of  the  house." 

One  of  the  effects  of  this  clause  has  already  been 
referred  to.  Another  is  that,  where  the  clause  is  enforced, 
new  houses  cannot  be  built  to  replace  the  old  ones,  in 
those  districts  where  a  water  supply  cannot  be  obtained 
at  a  "  reasonable "  cost,  because  water  certificates  will 
not  be  granted.  The  inhabitants,  therefore,  must  continue 
to  tenant  the  old  cottages,  however  dilapidated,  unless 
the  latter  be  condemned.  In  such  cases  the  L.A.  must 
either  provide  a  public  supply,  and  so  enable  new  cottages 
to  be  erected,  or  the  people  must  be  allowed  to  tenant 
the  old  places,  or  be  turned  out  to  find  homes  elsewhere. 

P.H.W.A.*  (9).  Where  the  L.A.  provide  stand  pipes 
they  may  recover  water-rates  or  water-rents  from  the 
owners  or  occupiers  of  every  dwelling-house  within  200 
feet  of  the  stand  pipe,  unless  such  house  has  a  good  supply 
of  its  own. 

The  L.A.,  therefore,  can  provide  stand  pipes,  and 
charge  rates  on  all  the  houses  using  the  water  within  200 
feet  of  each.  Houses  beyond  this  distance  cannot  be 
rated.  In  one  of  my  districts  numerous  stand  pipes  are 
provided,  and  the  owners  need  not  lay  on  the  water  to 
the  houses.  In  another,  stand  pipes  are  only  provided 
under  exceptional  circumstances,  and,  wherever  possible, 
the  owners  are  compelled  to  lay  on  the  water  to  the 
houses.  By  carrying  a  service  main  within  200  feet  of  a 
house  not  having  a  proper  supply  of  water,  and  fixing  a 
stand  pipe,  the  house  can  be  rated. 

P.H.W.A.  (8).  Upon  application  to  the  Local  Govern- 
ment Board,  the  Board  may  fix  a  general  scale  of  charges, 
instead  of  the  fixed  charge  referred  to<  in  (3). 

The  "  Limited  Owners  Reservoirs  and  Water  Supply 
Further  Facilities  Act,  1877,"  enables  a  landowner  to 
charge  his  estate  with  the  cost  of  constructing  works  for 

*  This  section  applies  to  Rural  Sanitary  Authorities  only. 


THE  LAW  RELATING  TO   WATER  SUPPLIES         465 

the  supply  of  water  thereto,  or  he  may  enter  into  an 
agreement  with  the  L.A.  or  any  company  or  person  for 
the  supply  of  water  for  any  term  not  exceeding  the 
number  of  years  during  which  the  cost  of  the  improvement 
is  a  charge  on  the  estate. 

The  following  sections  are  from  the  Water  Works  Clauses 
Acts  of  1847  and  1863:- 

(1847  Act.)  Sec.  44.  Requires  the  L.A.  to  lay  down 
communication  pipes,  etc.,  to  any  dwelling-house  (under 
£10  rental)  situate  in  any  street  where  they  have  laid 
pipes  (1)  either  at  the  request  of  the  owner,  or  (2)  at  the 
request  of  the  occupier,  upon  payment  or  tender  of  the 
water-rate  in  respect  of  such  house,  by  this  Act  made 
payable  in  advance. 

Sec.  46.  The  L.A.  are  at  liberty,  on  refusal  to  pay  for 
water,  to  remove  pipes  and  recover  expenses. 

Sec.  58.  Imposes  a  penalty  on  occupiers  or  owners  of 
premises  permitting  people  who  are  not  entitled  to  a 
supply  of  water  to  take  water  from  their  pipes. 

Sec.  59.  Any  person  taking  water  without  right  is  liable 
to  a  penalty  of  <£10. 

Sec.  60.  Any  person  wilfully  injuring  any  lock,  cock, 
valve,  etc.,  is  liable  to  a  penalty. 

(1863  Act.)  Sec.  12.  A  supply  of  water  for  domestic 
purposes  shall  not  include  a  supply  for  cattle,  or  for 
horses,  or  for  washing  carriages,  where  such  horses  or 
carriages  are  kept  for  sale  or  hire,  or  a  supply  for  any 
trade,  manufacture,  or  business,  or  for  watering  gardens, 
or  for  fountains,  or  for  any  ornamental  purposes. 

Sees.  17  to  19.  Impose  penalties  for  waste  or  misuse 
of  water  or  for  unauthorised  alteration  of  service  pipes. 

The  Justice  of  the  Peace  of  8th  June,  1895,  commenting 
on  the  provisions  of  the  Public  Health  Act,  1875,  as 
affecting  water  supplies,  says :  "  Turning  now  to  the 
provisions  of  the  Public  Health  Act,  we  find  there  a 
code  of  rules  regulating  the  manner  in  which  a  water 

3° 


466  WATER  SUPPLIES 

supply  is  to  be  carried  on  by  the  District  Council.  We  do 
not  intend  to  go  through  the  sections,  but  only  to  call 
attention  to  one  or  two  matters  as  affected  by  recent 
decisions.  An  interesting  case  arose  under  section  64  of 
the  Public  Health  Act,  1875 — the  case  of  Holmfirth  Local 
Board  v.  Shore — which  we  reported  in  last  week's  issue, 
ante,  p.  344.  By  that  section,  all  existing  public  cisterns, 
pumps,  wells,  reservoirs,  conduits,  aqueducts,  and  works 
used  for  the  gratuitous  supply  of  water  to  the  inhabitants 
of  the  district  of  any  Local  Authority,  are  to  vest  in  and 
be  under  the  control  of  such  Authority.  In  the  Holmfirth 
case,  it  appeared  that  at  Holmfirth  there  was,  near  the 
top  of  a  hill,  a  well  called  Flacketer  Well,  supplied  by  a 
natural  spring  of  water,  flowing  into  a  trough  or  cistern, 
and  the  overflow  ran  down  the  hill  to  another  well  or 
trough,  or  cistern  of  stone,  called  Ing  Head  Well  or 
Trough.  It  was  the  Ing  Head  Well  that  was  the  subject 
of  the  litigation.  The  overflow  from  this  place  ran  down 
the  hill  to  a  third  well  or  trough  or  cistern  in  South 
Lane.  It  was  in  evidence  that  the  Ing  Head  Well  had 
been  used  by  the  neighbouring  inhabitants  for  drawing 
water  for  domestic  purposes,  and  for  watering  cattle, 
without  any  interference  or  opposition  from  any  one  for 
more  than  fifty  years.  Prior  to  the  existence  of  the 
Plaintiff  Authority,  the  district  in  which  Ing  Head  Well 
was  situated  had  been  under  the  Wooldale  Local  Board, 
and  that  Board  had  laid  pot  pipes  instead  of  a  brick 
rubble  drain  from  Flacketer  Well  all  the  way  to  South 
Lane.  The  Wooldale  Local  Board  and  other  Local 
Authorities  subsequently  amalgamated,  and  formed  the 
present  Authority.  In  1884  the  defendant,  who  occupied 
a  house  near  Ing  Head  Well,  put  up  a  gate  to  keep 
cattle  away  from  it,  and  began  to  try  to  prevent  the 
public  from  using  it.  Subsequently,  he  put  a  pipe  in  the 
bottom  of  the  trough,  leading  into  his  own  house,  where 
it  terminated  in  a  stopcock,  and  by  means  of  this  pipe 


THE  LAW  RELATING  TO  WATER  SUPPLIES         467 

and  stopcock  he  could  draw  off  all  the  water  in  the  trough, 
or  as  much  as  he  pleased.  Among  the  defences  set  up 
before  the  County  Court  Judge  was  the  defence  that  a 
trough  was  not  a  well  at  all,  nor  anything  else  mentioned 
in  section  64.  But  the  County  Court  Judge  found  as  a 
fact  that  it  was  a  well  within  the  meaning  of  the  section. 
On  the  question  whether  it  vested  in  the  Plaintiff 
Authority  within  the  meaning  of  the  sections,  he  also 
found  that  it  did.  These  findings  were  seriously  contested 
in  the  Divisional  Court,  but  the  appeal  failed.  Day,  J., 
said  :  '  After  looking  at  the  photograph,  I  have  come  to 
the  conclusion  that  this  is  not  a  "  well,"  but  a  "  public 
cistern,  reservoir,  conduit,  or  aqueduct,"  or  certainly  a 
"  work  used  for  the  gratuitous  supply  of  water,"  within 
the  meaning  of  section  64  of  the  Public  Health  Act,  1875, 
and  I  cannot  find  any  fault  with  the  decision  of  the 
learned  County  Court  Judge  that  it  comes  under  one  or 
other  of  these  descriptions.'  Wright,  J.,  on  the  question 
of  the  '  well '  vesting  in  the  Local  Authority,  said : 
'  The  leading  authority,  so  far  as  I  know,  for  construing 
those  words,  "  vest  in  and  be  under  the  control  of,"  as 
regards  streets,  is  now  the  case  of  Wandsworth  Board  of 
Works  v.  United  Telephone  Company,  48  J.  P.  676,  and  it 
seems  to  me  to  be  applicable  to  wells  as  well  as  to  streets. 
Looking  at  that,  and  the  other  cases  as  to  streets,  it  seems 
to  me  now  impossible  to  deny  that  the  Local  Authority 
have,  in  respect  of  the  streets  and  wells  vested  in  them 
by  force  of  the  statute,  a  right  of  property — not  an 
absolutely  unqualified  right  of  property,  but  one  capable 
of  limitation  in  point  of  time,  and  limited  in  some  respects 
as  regards  user — but  still  a  right  of  property  and  of 
possession  which  is  sufficient  to  enable  them  to  complain 
of  anything  that  interferes  at  allr  not  merely  that 
injuriously  interferes,  with  their  occupation  of  the  street 
or  well  for  the  purposes  for  which  it  is  vested  in  them  by 
the  statute.  Now,  certainly,  the  boring  of  a  hole  a't  the 


468  WATER  SUPPLIES 

bottom  of  a  cistern  or  well  must  interfere,  whether 
injuriously  or  not,  with  the  possession  of  it  as  a  cistern 
or  well.  Therefore,  on  that  point,  the  judgment  of  the 
learned  County  Court  Judge  was  right.' 

"  A  similar  question  arose  under  the  Public  Health 
(Scotland)  Act,  1867.  By  section  89  (4)  of  that  Act 
'  the  Local  Authority  may  cause  all  existing  public  cisterns, 
pumps,  wells,  reservoirs,  conduits,  aqueducts,  and  works 
used  for  the  gratuitous  supply  of  water  to  the  inhabitants 
to  be  continued,  maintained,  and  plentifully  supplied  with 
water.'  It  will  be  observed  that  the  '  wells '  do  not  vest 
in  the  Local  Authority ;  it  merely  enables  the  Local 
Authority  to  cause  them  to  be  maintained.  In  Smith  v. 
Archibald,  5  <App.  Cas.  489,  the  alleged  rights  of  the 
owner  and  the  rights  of  the  Local  Authority  came  in 
dispute.  It  appeared  that  there  was  a  well  in  the  corner 
of  a  private  field.  A  footpath  ran  from  the  road  to  the 
entrance  of  the  field,  and  a  cart-road  from  this  entrance 
to  the  public  road,  going  through  the  village  of  Denny. 
The  inhabitants  of  this  village  had  for  a  prescriptive 
period  used  the  water  of  the  well  for  domestic  purposes, 
and  had  had  the  well  cradled  with  stones  at  their  own 
expense.  The  Local  Authority  caused  the  well  to  be 
covered  in  with  an  iron'  plate,  and  placed  therein  a  hand 
pump  with  the  avowed  object  of  keeping  the  well  free 
from  pollution.  The  proprietor  of  the  field  claimed  the 
well  as  his  private  property,  and  instituted  proceedings 
to  have  the  cover  and  pump  removed.  The  House  of 
Lords  held  that  the  well  was  a  public  well  within  the 
meaning  of  section  89  (4),  supra,  and  the  Local  Authority 
had  not  done  anything  in  excess  of  their  powers." 


CHAPTER    XXV. 

RURAL  AND  VILLAGE  WATER  SUPPLIES. 

PROBABLY  every  centre  of  population  in  the  United 
Kingdom  which  aspires  to  the  dignity  of  being  called  a 
town  has,  at  the  present  time,  some  form  of  waterworks, 
of  a  more  or  less  satisfactory  character,  supplying  water 
by  means  of  mains  for  the  use  of  the  inhabitants.  For 
certain  reasons  it  has  been  assumed  that  villages  and  hamlets 
and  rural  districts  generally  could  not  be  so  supplied, 
and  the  conditions  as  to  water  supply  continue  much  as 
they  have  been  from  time  immemorial.  In  rural  districts, 
especially  of  an  agricultural  character,  the  inhabitants  are 
very  conservative  in  character,  too  prone  to  be  satisfied 
with  things  as  they  are,  and  too  lethargic  to  strongly 
desire  or  to  express  a  desire  for  change,  especially  if  such 
change  will  throw  any  additional  burden  on  the  rates. 
What  was  good  enough  for  their  forefathers  is  good 
enough  for  them.  They  have  grown  up  under  conditions 
to  which  they  have  become  accustomed,  and  their 
exceedingly  limited  experience  of  other  conditions  does 
not  enable  them  to  comprehend  the  advantages  which  may 
be  derived  from  a  change.  Where  a  public  supply  has 
been  introduced  into  a  village,  it  has  frequently  been  as 
the  result  of  an  outbreak  of  some  disease,  an  epidemic  which, 
in  all  probability,  would  have  been  avoided  had  a  proper 
supply  been  obtained  earlier.  In  rural  districts  also  the 
population  is  scattered.  A  parish  may  contain  a  fairly 
compact  village,  or  it  may  contain  one  or  more  groups  of 

(469) 


470  WATER  SUPPLIES 

houses  which  may  be  called  hamlets,  or  the  cottages  may 
be  scattered  over  the  whole  area.  In  any  case,  to  supply 
a  given  number  of  houses  much  longer  mains  are  required 
than  in  a  town,  and  the  cost  of  obtaining  a  public  supply 
is  proportionately  increased.  Again,  the  wages  earned  in 
the  country  are  much  lower  than  in  the  towns,  and  the 
poorer  classes  are  the  less  able  to  bear  any  additional 
burden  in  the  form  of  rates.  Unfortunately,  also,  land- 
owners and  property  owners  generally  are  affected  by  the 
depressed  state  of  agriculture,  and  do  not  look  with  favour 
upon  any  scheme  which,  however  much  it  may  benefit 
the  inhabitants,  will  not  apparently  confer  any  immediate 
benefit  upon  themselves,  or  an  advantage  in  their  opinion 
not  commensurate  with  the  expense  they  will  have  to 
bear.  Still  another  difficulty  arises  from  the  fact  that 
under  the  Public  Health  (Water)  Act,  1878,  no  newly- 
erected  house!  can  be  inhabited  without  the  Sanitary 
Authority  having  certified  that  there  is  within  a  reason- 
able distance  an  available  supply  of  wholesome  water. 
There  is  no  definition  of  the  words  "  reasonable  distance," 
"  available  supply,"  and  "  wholesome,"  and  they  are  very 
differently  interpreted  by  different  authorities.  By  some, 
a  quarter  of  a  mile  is  considered  a  "  reasonable  distance," 
a  water  obtained  on  sufferance  from  a  neighbour's  property 
is  considered  "  available,"  and  tank  water,  pond,  or  even 
ditch  water  is  considered  "  wholesome."  A  well  water 
is  almost  invariably  considered  to  be  good  whatever  its 
source  or  the  character  of  the  surroundings  of  the  well. 
In  growing  villages,  therefore,  we  have  often  a  large 
proportion  of  the  houses  rejoicing  in  the  possession  of 
these  certificates,  and  if  the  Authority  or  its  officers 
propose  a  public  supply  they  are  forthwith  produced  to 
prove  that  such  is  not  required.  If  an  owner  has  really 
been  put  to  considerable  expense  to  obtain  a  reasonably 
good  water,  it  seems  somewhat  unjust  that  he  should 
afterwards  be  called  upon  to  contribute  towards  a  similar 


RURAL  AND  VILLAGE  WATER  SUPPLIES  471 

benefit  being  conferred  upon  the  tenants  of  other 
properties,  whose  owners  have  failed  to  obtain  such  a 
supply.  In  rural  districts,  also,  the  officers  employed 
rarely  receive  such  remuneration  as  secures  the  services 
of  men  with  wide  experience,  capable  of  working  out  the 
details  of  a  waterworks  scheme,  and  presenting  it  to 
the  Authority  so  as  to  show  its  feasibility  and  convince 
them  of  its  great  advantages  or  of  its  necessity.  Unless 
they  are  able  to  do  this  there  is  little  likelihood  of  public 
water  supplies  being  generally  adopted  in  our  villages 
and  rural  districts.  The  initial  expense  of  calling  in  an 
engineer  will  have  to  be  borne  by  the  general  rates  unless 
a  scheme  be  ultimately  accepted  and  carried  out.  At  this 
stage  it  may  be  doubtful  whether  it  is  possible  to  obtain 
a  supply  at  a  reasonable  cost,  and  th©  Authority  naturally 
hesitates  at  incurring  this  expense.  I  am  perfectly  con- 
vinced that  none  of  the  parishes  in  my  districts,  which  are 
now  enjoying  all  the  advantages  of  having  water  mains 
ramifying  in  their  midst,  would  ever  have  been  so  supplied 
had  not  the  Surveyor  been  able  to  (draw  up  all  the  details 
of  the  various  schemes,  prepare  the  plans,  and  superintend 
the  carrying  out  of  the  works.  Confidence  engendered  by 
the  successful  execution  of  one  scheme,  and  the  ultimate 
expressions  of  appreciation  by  those  who  at  first  opposed 
the  innovation  (for  these  are  usually  the  first  to  acknow- 
ledge its  advantages),  pave  the  way  for  further  extensions, 
and  make  each  successive  step  in  the  inarch  of  sanitary 
progress  less  difficult. 

That  the  water  supplies  of  our  parishes,  derived  from 
shallow  wells,  pools,  ponds,  land  springs,  rain-water  tanks, 
or  the  hawker's  cart,  are  often  miserably  inadequate  in 
quantity,  and  most  unsatisfactory  in  quality,  requires  no 
proof  beyond  that  already  given  in  preceding  chapters  of 
this  work.  Neither  is  it  necessary  to  dwell  upon  the 
advantages  of  having  an  abundant  supply  of  pure  water 
which  can  be  drawn  from  the  tap  at  the  very  door,  or, 


472  WATER  SUPPLIES 

better  still,  within  the  house,  so  conducing  to  the  cleanli- 
ness of  person,  cleanliness  of  the  household,  and  of  the 
parish  generally.  Cleanliness  may  not  be  next  to  godli- 
ness, but  its  importance  in  maintaining  health  and  vigour 
is  too  well  established  to  need  further  demonstration. 
It  is  much  to  be  regretted  that  whilst  this  is  universally 
admitted  with  reference  to  man,  it  still  appears  to  be 
entirely  ignored  with  regard  to  cattle.  Yet,  the  vital 
processes  in  the  one  are  so  closely  akin  to  those  in  the 
other  that  it  does  not  admit  of  reasonable  doubt  that  all 
the  conditions  which  make  for  health  in  the  one  are 
necessary  for  the  other.  Of  especial  importance  to  us, 
however,  is  cleanliness  in  connection  with  milch  cows  and 
dairy  farms,  since  in  this  country  it  is  almost  universal 
custom  to  consume  the  milk  raw.  Milk  contains  all  the 
necessary  ingredients  for  supporting  life ;  not  only  the  life 
of  the  higher  types  of  the  animal  kingdom,  but  also  that 
of  those  lowest  forms,  be  they  animal  or  vegetable,  the 
so-called  microbes,  many  of  which,  when  they  gain  access 
to  the  human  system,  are  capable  of  producing  disease. 
Some  of  these  multiply  with  extraordinary  rapidity  when 
introduced  into  milk,  and  alarming  outbreaks  of  disease 
have  been  traced  to  such  infected  milk.  There  is  little 
doubt  that  many  of  these  epidemics  could  have  been 
prevented  had  the  cattle  been  supplied  with  more  whole- 
some water,  had  the  milk-cans  been  cleansed  with  pure 
water,  and  had  the  teats  of  the  cows  and  the  milker's 
hands  been  cle>an.  The  importance  of  an  abundant  supply 
of  pure  water  for  dairies  and  dairy-farms  is  an  additional 
argument  in  favour  of  public  rural  supplies. 

Where:  water  mains  are  laid  in  rural  districts,  the 
erection  of  cottages  and  houses  is  encouraged,  since  the 
owners  are  no  longer  under  the  necessity  of  sinking  wells, 
constructing  rain-water  tanks,  fixing  pumps,  etc.,  with 
their  initial  expense  and  perpetual  trouble  to  keep  in 
repair.  Very  often  the  interest  on  the  original  expendi- 


RURAL  AND  VILLAGE   WATER  SUPPLIES  473 

ture  for  a  well  and  pump  exceeds  that  of  the  water  rate 
which  would  suffice  to  pay  for  a  public  supply. 

The  difficulties  in  the  way  of  supplying  thinly-populated 
areas  with  water  have  been  greatly  overrated,  and 
probably  in  few  cases  are  they  insurmountable.  In 
recommending  a  really  good  scheme,  one  can  always  feel 
the  utmost  confidence  in  asserting  that,  however  much  it 
may  be  opposed  by  those  intended  to  be  benefited,  and 
local  opposition  always  arises  when  a  Sanitary  Authority 
decides  to  provide  waterworks),  the  works  will  not  be  in 
existence  long  before  the  growlings  are  replaced  by  grate- 
ful acknowledgments  of  the  boon  conferred.  Simple  and 
inexpensive  supplies  can  often  be  obtained  by  collecting 
the  water  from  a  spring,  and  laying  mains  from  the 
reservoir  or  tank  to  hydrants  along  the  route.  Where 
pumping  is  necessary  the  motive  power  may  often  be 
obtained  by  aid  of  a  ram,  turbine,  or  water-wheel,  at  a 
reasonable  initial  expense,  and  at  a  cost  of  very  few 
shillings  per  year  for  attention  and  repairs.  If  thesa 
machines  cannot  be  utilised,  a  windmill  may  be  employed ; 
although,  on  account  of  the  large  size  of  the  storage  tank 
necessary,  the  expense  in  the  first  instance  will  be  some- 
what greater.  Gas,  oil,  and  hot-air  engines  also  require 
but  little  attention,  and  only  such  as  can  be  given  by  an 
intelligent  labourer.  The  weekly  labour  bill,  however, 
is  an  important  item  when  the  works  are  small,  but 
sometimes  a  supply  of  water  near  at  hand  can  be  utilised 
by  pumping  with  one  of  these  machines,  whereas  the 
nearest  source  available  for  working  a  ram  or  similar 
machine  may  be  a  considerable  distance  away.  In  such  a 
case  the  cost  of  pumping  may  be  less  than  the  interest 
on  the  extra  outlay  which  would  be  involved  in  laying 
the  additional  mains. 

In  connection  with  this  subject  it  will  probably  be  of 
interest  to  record  what  has  been  done  in  a  few  districts 
in  the  way  of  supplying  water  to  villages,  hamlets,  and 
scattered  cottages  therein.  What  has  been  done  here 


474  WATER  SUPPLIES 

may  be  done  elsewhere,  and  the  examples  given,  showing 
how  certain  difficulties  have  been  overcome,  may  be 
incentives  to  others  to  attempt  to  do  for  our  rural  districts 
what  has  already  been  so  well  done  for  our  towns. 

The  Nantwich  Rural  Sanitary  Authority  *  may  fairly 
claim  to  be  pioneers  in  carrying  water  mains  through 
thinly-populated  rural  districts.  They  commenced  in 
1878  by  supplying  the  township  of  Church  Coppenhall, 
and  since  then  the  mains  have  been  extended,  until,  at 
the  end  of  1893,  the  Authority  had  supplied,  in  32  town- 
ships, 2,817  houses,  with  a  population  of  upwards  of 
14,000.  There  are  93  miles  of  mains,  and  extensions 
involving  the  laying  of  27  more  miles  have  been  decided 
upon.  "  The  cottages  are  supplied  with  water,  pure  in 
quality,  plentiful  in  quantity,  and  conveniently  at  hand, 
with  taps  within  each  house,  at  twopence  farthing  per 
week."  This  payment  by  the  tenants,  however,  does  not 
cover  the  whole  cost  of  the  supply.  The  mode  in  which 
this  is  defrayed  is  thus  described  by  Mr.  Davenport,  the 
engineer  and  surveyor  to  the  district. 

"  Supposing  the  cost  of  a  water  supply  to  a  township  is 
£1,000,  the  annual  charge  upon  that  amount  borrowed 
from  the  Public  Works  Loan  Commissioners  would  be 
about  £60  per  annum,  which  would  clear  off  principal 
and  interest  in  thirty  years.  Supposing  there  are  sixty 
houses  to  be  supplied,  the  annual  cost  of  furnishing  the 
water,  founded  upon  the  average  quantity  of  water  con- 
sumed per  house  (as  shown  in  the  Authority's  statistical 
tables  from  actual  measurement  and  cost),  would  be  about 
£18  per  annum,  making  a  total  expenditure  of  £78  per 
annum.  Taking  thirty  of  the  houses  to  bring  in  20s. 
each  per  annum  to  the  water  rate,  and  the  other  thirty 
to  bring  in  10s.  each,  which  is  the  minimum,  the  water 
rate  would  only  raise  £45  per  annum,  leaving  a  deficiency 
against  the  township  of  £33  per  annum  for  thirty  years. 

*  "  Public  Waterworks  for  Rural  Districts."  J.  A.  Davenport,  C.E., 
Surveyor,  Nantwich,  R.S.D.  (Sanitary  Record,  3rd  March,  1894). 


RURAL  AND  VILLAGE  WATER  SUPPLIES  475 

By  the  system  of  guarantee  referred  to  (a  guarantee  on 
the  part  of  the  owners  of  estates  benefited,  to  pay  a  sum 
not  exceeding  6d.  per  acre  per  annum  for  thirty  years), 
the  owners  of  property  step  in  and  pay  this,  and  where 
either  the  whole,  or  a  considerable  portion  of  a  township, 
is  supplied  by  these  public  mains,  Id.  in  the  pound,  if 
needed,  is  contributed  by  the  general  township  rate,  in 
reduction  of  the  deficiency.  It  will  make  some  little 
difference  at  first,  whether  the  money  is  lent  to  be  repaid 
by  equal  annual  instalments,  or  annual  instalments  of 
principal  and  interest ;  in  the  former  case,  the  instalments 
being  the  same  each  and  every  year,  and  in  the  latter 
they  are  rather  heavier  for  the  first  fifteen  years,  and 
lighter  for  the  last  fifteen  years."  This  system  of 
guarantee  has  been  very  successful  in  this  district, 
and  several  landowners  have  also  ,  given  considerable 
amounts  for  the  laying  of  mains  for  the  benefit  of 
property  with  which  they  are  connected. 

The  Maldon  Rural  District  Council  have  just  completed 
a  scheme  for  supplying  eight  parishes  with  water.  The 
total  population  is  only  2,437,  spread  over  an  area  of 
20,000  acres.  There  are  26  miles  of  mains.  The  water  is 
derived  from  a  spring  which  yields  from  60,000  to  100,000 
gallons  per  day  of  excellent  water.  The  pumping  station 
is  near  the  springs,  and  the  plant  consists  of  two  vertical 
boilers,  two  horizontal  duplex  steam  pumps  so  arranged 
that  either  boiler  will  supply  steam  to  either  pump.  The 
duty  of  each  pump  is  to  deliver  6,000  gallons  of  water  per 
hour  through  a  rising  main  1,200  yards  long  into  the 
service  reservoir  on  ground  110  feet  above  the  pumping 
station.  This  reservoir  is  constructed  of  Portland  cement 
concrete,  partly  below  and  partly  above  the  surface  of  the 
ground,  and  supplies  the  various  parishes  with  water 
through  the  26  miles  of  mains.  Stand  posts  are  fitted  at 
the  ends  of  all  the  branches,  and  along  the  route.  They 
are  of  the  banjo  pattern,  fitted  with  self-closing  cocks, 
which  can  only  be  opened  by  a  key. 


476  WATER  SUPPLIES 

A  large  proportion  of  the  cottages  and  farms  will  be 
directly  connected  with  the  mains.  The  total  cost  was  close 
upon  £13,000.  The  district  is  purely  agricultural,  and  the 
rateable  value  is  only  £5,630.  The  cottages  are  supplied 
with  water  at  a  rate  of  2d.  per  week.  Most  of  the  farms  are 
supplied  by  meter.  The  estimated  revenue  from  water  rents 
and  rates  is  £408  per  annum.  The  balance  is  raised  with 
the  sanitary  rate.  The  whole  of  the  works  were  designed 
and  carried  out  by  Mr.  H.  G.  Keywood,  the  Council's  Sur- 
veyor and  Engineer,  and  admirably  exemplify  what  can  be 
done  in  a  purely  rural  district. 

Similar  works  of  equal  magnitude  have  been  in  exist- 
ence some  years  in  the  adjoining  Rural  District  of 
Chelmsford,  and  every  year  the  mains  have  to  be  extended 
to  meet  the  constantly  increasing  demand  for  water.  The 
demand  has  already  become  so  great  that  the  District 
Council  have  acquired  an  additional  spring  and  connected 
it  with  the  existing  system. 

Spring  and  Rain. — In  another  small  village  in  one  of 
my  districts  a  spring  rising  at  the  outskirts  supplies  a 
ram,  which  pumps  water  into  a  tower  supported  upon  iron 
columns.  The  tank  has  a  capacity  of  1,200  gallons.  The 
water  is  laid  on  to  several  houses  and  to  stand  pipes  in 
the  street.  The  total  cost  was  only  £200 ;  a  portion  was 
raised  by  subscription,  and  the  remainder  paid  out  of  the 
rates,  the  payment  being  extended  over  three  years. 

Spring  and  Steam  Pumping. — In  another  parish,  with 
321  houses  and  a  population  of  1,303,  a  water  supply  has 
been  inaugurated  which  furnishes  water  to  about  two- 
thirds  of  the  population.  Over  a  spring  yielding  some 
30,000  gallons  of  water  per  day  a  covered  tank  holding 
12,000  gallons  has  been  constructed.  Upon  a  brick  tower, 
70  feet  high,  a  wrought-iron  tank  holding  15,000  gallons 
has  been  fixed.  The  water  is  raised  from  the  spring  to 
the  tank  by  a  six  h.p.  engine,  through  4-inch  suction  and 
rising  mains.  From  the  tank  it  flows  through  over  2 


RURAL  AND  VILLAGE  WATER  SUPPLIES  477 

miles  of  mains  4-inch,  3-inch,  and  2-inch  in  diameter,  to 
supply  the  village.  The  total  cost,  including  the  land  and 
spring  (which  are  in  an  adjoining  parish),  was  slightly 
over  £2,000.  The  cost  of  pumping,  including  wages,  is 
about  £45  a  year.  The  loan  and  interest  is  being  repaid 
in  equal  half-yearly  instalments,  spread  over  a  term  of 
thirty  years.  An  annual  sum  of  £25  is  paid  for  the 
water  supplied  to  a  malt  kiln,  and  a  small  sum  is  paid  out 
of  the  general  rate  for  the  water  used  for  road  watering, 
etc. ;  the  balance  is  raised  by  a  rate  of  Is.  4d.  in  the  pound 
levied  on  the  users  of  the  water. 

Spring  Water  raised  by  a  Water-wheel. — The  hamlet  of 
Cressbrook,  near  Buxton,  Derbyshire,  has  recently  been 
supplied  with  spring  water  by  pumping,  and  the  following 
description  of  the  works  has  been  furnished  by  the 
engineers,  Messrs.  J.  and  J.  Webster,  of  Bridge  Street, 
Buxton  :  — 

'  "  The  spring  water  is  conveyed  for  a  distance  of  400 
yards  through  3-inch  cast-iron  pipes,  where  it  is  delivered 
into  a  cistern  of  120  gallons  capacity.  The  power  is 
obtained  for  driving  the  pump  with  a  breast-water  wheel, 
8  feet  diameter  by  4  feet  wide,  constructed  of  iron  and 
Siemens  steel.  The  driving  water  *  to  the  wheel  is  also 
carried  a  distance  of  400  yards.  To  the  water-wheel  is 
attached  a  three-cylinder  pump,  specially  designed  and 
constructed  by  us,  to  meet  the  exceeding  high  pressure 
(200  Ib.  per  square  inch)  and  give  a  constant  flow.  The 
water  is  drawn  from  the  above  cistern  and  delivered 
through  1,125  feet  of  3-inch  pipe  to  the  reservoir,  situated 
410  feet  higher  than  the  pump.  The  reservoir  has  a 
capacity  of  35,000  gallons,  and  is  cut  out  of  the  solid 
limestone  rock,  which  is  lined  with  a  wall  2  feet  thick, 
then  lined  with  bricks  set  in  cement,  and  further  grouted 
between  the  brickwork  and  wall  with  fine,  clean  gravel 
and  cement.  The  reservoir  is  divided  into  two  halves, 
so  that  one  half  can  be  working  whilst  the  other  half  is 

*  Derived  from  the  river  Wye. 


478  WATER  SUPPLIES 

being  cleaned  out.  The  supply  to  the  houses,  Cressbrook 
Hall,  and  mills  is  through  3-inch  cast-iron  gravitation 
pipes.  The  taps  are  enclosed  in  cast-iron  boxes,  specially 
designed  to  protect  them  from  frost.  Provision  has  been 
made  at  the  mills  to  use  the  water  in  case  of  fire.  When 
tested  with  a  hydrant  it  was  found  that  a  stream  of  water 
could  be  thrown  about  20  feet  higher  than  the  roof  of 
the  mills.  The  total  length  of  pipes  is  about  2  miles. 
All  the  cast-iron  pipes  are  coated  by  Dr.  Angus  Smith's 
process.  The  quantity  of  water  guaranteed  to  be  delivered 
into  the  reservoir  is  from  3,000  to  4,000  gallons  per  day, 
but  12,000  gallons  can  be  delivered  without,  running  wheel 
and  pumps  at  an  excessive  speed." 

The  total  cost  was  a  little  under  £1,000,  and  was 
borne  by  the  owner  of  the  estate.  The  water  is  laid  on 
to  15  stand  pipes  for  the  supply  of  the  cottages,  and  a 
charge  of  IJd.  per  week  is  made  for  the  use  of  the  water. 

Deep-well  Water  raised  by  a  Windmill. — At  Lechlade, 
Gloucestershire,  a  windmill  has  been  successfully  used  for 
supplying  the  village  with  water.  The  population  is  1,250, 
and  the  number  of  inhabitants  supplied  about  1,000.  The 
windmill  was  made  by  the  Ontario  Company,  and  has 
sails  of  18  feet  diameter.  The  pumps  are  double-action, 
with  4-inch  cylinders.  A  tank  capable  of  holding  60,000 
gallons  of  water  is  supported  on  a  brick  tower  10  feet 
high,  in  which  the  pumps  are  placed,  and  on  the  top  of 
this  is  the  windmill  working  a  shaft  passing  through  the 
tanks  to  the  pumps  which  are  directly  over  the  well.  The 
well  is  a  tubular  one  4  inches  in  diameter,  driven  to  a 
depth  of  24  feet  through  a  bed  of  clay  into  water-bearing 
gravel.  The  windmill  has  an  automatic  action,  shutting 
off  when  the  tank  is  full  and  collapsing  when  the  wind 
pressure  is  beyond  that  for  which  the  sails  are  set.  The 
supply  has  never  failed  during  the  four  years  the  works 
have  been  in  existence,  the  storage  in  the  tank  having 
proved  ample  to  tide  over  the  calm  periods  when  the 
pumps  were  out  of  action.  The  water  is  supplied  to 


RURAL  AND  VILLAGE   WATER  SUPPLIES  479 

stand  pipes  in  the  streets,  but  any  house  can  have  it  laid 
on  by  paying  a  rate  of  10s.  a  year.  The  money  was 
borrowed  by  the  Sanitary  Authority  and  has  to  b©  paid  off 
in  thirty  years.  The  water  rate  is  3d.  in  the  pound. 
Messrs.  Johns  Brothers,  Lechlade  Foundry,  carried  out 
the  scheme,  from  the  designs  of  Mr.  J.  H.  Bardfield, 
London.  The  total  cost  of  the  works  was  £1,800. 

Spring  Water  supplied  by  Gravitation. — The  village  of 
Winfrith,  Dorsetshire,  has  been  supplied  with  water  from 
a  spring  at  the  outskirts.  The  works  were  designed  and 
carried  out  by  Messrs.  Foster,  Lott,  and  Co.,  of  Dorchester. 
The  springhead  is  situated  on  the  hillside  above  the 
rectory  farm  and  close  to  the  Chaldon  road.  The  water 
springs  from  the  limestone  rock,  and  is  not  only  of 
organic  purity  but  is  remarkably  clear  and  sparkling. 
It  is  collected  at  the  very  springhead  into  a  perforated 
iron  container,  and  there  have  been  placed  around  the 
outside  of  the  container  several  hundred  loads  of  flint, 
gravel,  and  chalk.  There  is  a  12-inch  overflow,  the 
surplus  water  running  into  the  brook  course.  The  con- 
tainer and  chamber  are  hermetically  sealed,  and  the  water 
is  beyond  all  possible  chance  of  contamination  from  the 
foul  Chaldon  brook,  nor  can  it  be  intentionally  polluted. 
From  the  spring  the  water  is  conveyed  by  4-inch  casWron 
pipes  into  the  village,  and  waste-preventing  hydrants  of 
the  latest  pattern  are  placed  at  convenient  distances  for 
public  use.  There  is  quite  an  18  feet  head  at  the  spring, 
and  an  ample  pressure  to  carry  the  water  many  miles 
farther  if  required.  All  the  valves  are  Lambert's  high- 
pressure  diaphragm  valves,  of  the  same  pattern  as  at 
the  Dorchester  Waterworks,  as  also  are  the  boxes  and 
castings.  There  is  an  entire  absence  of  expense  after  the 
initial  outlay,  the  water  being  conveyed  by  the  natural 
force  of  gravity  to  the  various  deliveries. 

Spring  Water  pumped  by  a  Turbine. — The  waterworks 
at  West  Lulworth,  referred  to  in  Chapter  XIX.,  were 
also  designed  and  constructed  by  the  same  firm.  An 


480  WATER  SUPPLIES 

attempt  to  supply  West  Lulworth  with  water  was  made 
about  ten  years  ago,  a  spring  on  the  Bindon  Hills  having 
been  tapped  and  pipes  laid  on  to  various  points.  This 
was  opened  in  May,  1886,  the  whole  cost  having  been 
borne  by  the  Weld  estate ;  but  from  the  first  it  was  found 
to  be  wholly  inadequate.  The  reservoirs  and  pipes  being 
intact — the  former  situated  on  the  hillside  quite  300  feet 
above  the  sea-level — it  was  suggested  that  the  same  plant 
might  be  utilised.  Attention  was  directed  to  the  great 
spring  under  the  rocks  close  to  the  cove,  and  Mr.  Foster 
was  consulted.  A  portion  of  the  water  is  conveyed  from 
the  spring  to  the  old  mill-pond  on  the  other  side  of  the 
road,  which  has  been  thoroughly  cleared  out  and  now 
forms  quite  an  ornamental  lake,  to  pump  the  supply  to  the 
reservoirs  in  the  hillside  300  feet  above.  From  the  pond 
the  water  passes  to  the  top  of  a  new  stone  tower,  which 
contains  a  vortex  horizontal  turbine.  The  turbine  is 
fixed  in  the  pit  at  the  bottom  of  the  tower,  and  is  20  feet 
below  the  level  of  the  water  in  the  pond.  The  water 
falls  to  the  turbine  by  means  of  an  upright  vertical  pipe, 
the  waste  being  taken  at  the  bottom  by  a  12-inch  drain 
and  carried  to  the  sea.  From  the  turbine,  which  runs 
about  600  revolutions  per  minute,  the  power  is  com- 
municated by  a  10-inch  pulley  to  a  large  pulley  on  the 
over-head  shafting,  and  from  thence  the  power  is  trans- 
ferred to  a  set  of  high-pressure  three-throw  plunger  pumps. 
It  is  estimated  that  these  pumps,  driven  by  the  means 
mentioned,  which  are  equal  to  five  horse-power,  will  lift 
1,200  gallons  an  hour  continuously,  and  they  run  with  a 
surprising  degree  of  smoothness  and  absence  of  noise  or 
friction.  The  pumps  are  fitted  with  a  pressure  gauge 
which  not  only  registers  the  pressure  but  the ,  height  of 
the  water  in  the  pipes  and  tanks.  Notwithstanding  the 
recent  drought,  which  has  had  a  material  effect  on  the 
spring,  there  is  quite  sufficient  water  to  pump  up  more 
than  double  the  quantity  that  Mr.  Foster  contracted  to 
deliver  at  the  reservoir.  The  tower  is  built  of.  local 


RURAL  AND  VILLAGELWATER  SUPPLIES  481 

stone,  and  forms  quite  an  ornamental  feature  in  this 
pretty  village.  The  reservoirs  are  120  feet  by  20  feet, 
and  will  hold  60,000  gallons.  Formerly  they  were  un- 
covered, and  not  only  exposed  to  the  air  but  to  various 
contaminations.  They  are  now  covered  with  concrete, 
and  trapped  and  locked  in  the  same  way  as  the  spring  at 
Win  frith.  Besides  making  a  large  number  of  connections 
in  the  village,  a  set  of  hydrants  and  hose  for  use  in  case 
of  fire  have  been  provided. 

Deep-well  Water  raised  by  an  Oil  Engine. — At  a  recent 
gathering  of  Medical  Officers  of  Health,  Dr.  Ashby,  of 
Reading,  gave  a  very  interesting  account  of  the  water- 
works recently  established  for  the  supply  to  a  village 
(Sonning)  in  his  district.  He  stated  that  the  water  was 
derived  from  a  boring  in  the  upper  chalk,  75  feet  deep, 
yielding  about  70  gallons  per  minute.  The  reservoir  has 
a  capacity  of  35,000  gallons,  and  the  rising  main  from  the 
well  to  the  reservoir  is  4  inches  diameter  and  1,783  feet 
in  length.  The  main  enters  the  top  of  the  reservoir  at 
about  100  feet  above  the  level  of  the  water  in  the  bore- 
hole. The  reservoir  is  about  4,000  feet  from  the  com- 
mencement of  Sonning  village,  its  bottom  being  about 
48  feet  above  the  highest,  and  83  feet  above  the  lowest 
parts  of  the  village.  The  distributing  mains  consist  of 
4,390  feet  of  4-mch  pipe  and  3,935  feet  of  3-inch  pipe. 
There  are  sixteen  hydrants,  five  air-valves,  and  seven 
sluice-valves,  besides  one  on  the  draw-off  pipe  at  the 
reservoir.  The  engine-house  cost  £124,  the  engine  and 
pumps  £260,  the  tube  well  £73,  making  a  total  of  about 
£457  for  the  entire  pumping  station  and  well.  The  total 
cost  of  the  works  was  £1,840.  With  the  sanction  of  the 
Local  Government  Board  £1,800  was  borrowed;  of  that 
sum  £400  has  to  be  repaid  in  fifteen  years  and  £1,400 
in  thirty  years.  To>  repay  the  annual  instalments  of 
principal  and  interest,  and  to  cover  the  cost  of  pumping 
and  other  expenses,  a  rate  of  Is.  in  the  pound  on  houses 

31 


482  WATER  SUPPLIES 

and  3d.  on  land  is  required,  besides  the  water  rate  charged 
on  the  occupiers  of  premises  actually  supplied.  The 
charges  for  domestic  supplies  are  7s.  a  year  for  all  houses 
under  £14  rateable  value,  and  2J  per  cent,  on  the  rateable 
value  of  all  other  houses,  and  some  extra  charges  for 
farmyards,  cowkeeping,  and  livery  stables.  The  expense 
is  considerable,  but,  as  Dr.  Ashby  remarks,  "  it  would 
have  cost  but  little  more  to  have  supplied  a  considerably 
larger  place."  Sonning  has  a  population  of  515  persons, 
and  its  rateable  value  is  £4,398.  The  oil  engine  is  of 
two  brake  horse-power,  and  the  pumps  are  a  set  of  treble 
ram  pumps,  with  gun  metal  plungers  4  inches  in  diameter 
by  9  inches  stroke.  They  are  fixed  to  the  suction  pipe 
at  the  top  of  the  lining  tube  of  the  bore-hole.  Dr.  Ashby 
made  a  very  careful  series  of  observations,  showing  the 
capacity  of  the  pumps  and  the  cost  of  pumping.  He 
says : — 

"  From  ard  September  to  30th  September,  1894,  we 
pumped  31 J  hours  on  11  days.  During  the  whole  of  that 
time  I  was  present  and  took  exact  observations  of  all  the 
materials  which  were  consumed.  We  could  have  done  the 
pumping  in  four  days,  but  we  pump  more  frequently  in 
order  to  keep  a  good  stock  of  water  in  the  reservoir  in 
case  of  any  fire  occurring,  or  in  the  event  of  the  machinery 
requiring  any  repairs,  so  that  the  village  may  not  be 
without  water.  We  consequently  use  rather  m'ore  oil 
in  starting  the  engine  than  would  be  absolutely  necessary. 
In  that  time  the  pumps  made  57,397  revolutions,  an 
average  of  1,822.1  an  hour.  There  are  7.2  revolutions 
of  the  engine  to  1  revolution  of  the  pumps,  so  the  engine 
ran  at  an  average  speed  of  218.65  revolutions  per  minute. 
The  total  quantity  of  water  raised  was  75,764  gallons,  or 
an  average  of  2,405.2  per  hour.  The  supply  per  head  of 
the  population  per  day  was  about  7  gallons, 


RURAL  AND  VILLAGE   WATER  SUPPLIES  483 

The  consumption  of  materials  was  as  under :  — 

s.  d. 

12  gallons  of  tea  rose  oil       ....         at  5d.         5  0 

1  battery  charge at  Is.         10 

1£  zinc  for  battery at  3d.         0  4£ 

24  fluid  ounces  of  sulphuric  acid  .         .     at  2d.  per  Ib.        0  5£ 


Total  cost  of  material  consumed  by  the  engine    .        .  6  10 
3£  pints  of  lubricating  oil  for  engine  and 

pumps at  2s.  a  gall.  0  10 

Cotton  waste at  4d.  per  Ib.  0    3 


Total  cost  of  materials  consumed  by  engine  and  pumps  8  0 
Cost  of  materials  for  engine  per  1,000  gallons  of 

water  raised  100  feet  high  ....  1-082  penny 
Total  cost  of  materials  for  engine  and  pumps  per 

1,000  gallons  of  water  raised  100  feet  high  .  1-267  penny 
Consumption  of  oil  per  h.p.  per  hour  .  .  .  1-5  pint. 

Spring  Water  pumped  by  Gas  Engine. — Great  Baddow 
and  Springfield  are  two  adjoining  villages  with  a  popula- 
tion of  about  4,000.  The  waterworks  are  situated  in  a 
piece  of  ground  near  the  spring.  The  spring  yields  80,000 
to  100,000  gallons  per  day.  For  the  past  fifteen  years  one 
eight  horse-power  gas  (Crossley  Otto)  engine  and  set  of 
pumps  have  been  sufficient  to  raise  all  the  water  required ; 
but  recently  a  new  seven  horse-power  (Crossley  Otto)  engine 
with  a  set  of  three-throw  pumps  has  been  erected  as  a 
duplicate. 

There  are  four  reservoirs  24'  x  12'  x  6'  brick-built  and 
covered  with  brick  arches,  each  holding  10,350  gallons. 
The  water  is  pumped  twice  daily  from  these  reservoirs  to 
a  tank  holding  40,000  gallons  on  the  top  of  a  tower  96 
feet  high.  The  villages  are  then  supplied  by  gravitation. 

The  amount  of  gas  used  in  pumping  is  200  feet  per  hour 
for  the  new  engine  and  250  feet  per  hour  for  the  old 
engine.  Gas  at  3s.  4d.  per  1,000  feet.  The  total  expense 
for  working  is  about  £180  per  year,  exclusive  of  the  cost 
of  repairing  mains.  The  amount  of  water  rents  collected 
from  the  houses  supplied  is  about  £350  per  annum.  Where 
water  is  supplied  by  meter  the  charge  varies  from  Is.  6d. 
to  Is.  per  1,000  gallons,  according  to  the  amount  con- 
sumed. 


CHAPTER    XXVI. 

WATER  CHARGES. 

A  COMPARISON  of  the  charges  for  water  in  different 
places  is  a  difficult  matter.  In  some  districts  the  charges 
made  to  the  consumers  defray  the  total  cost  of  the  water 
including  repayment  of  principal  and  interest.  In  other 
cases  a  certain  portion  of  this  cost  is  paid  out  of  the 
General  Sanitary  Rate.  Where  the  waterworks  are  owned 
by  companies  the  prices  charged  may  or  may  not  include 
a  profit;  sometimes  the  water  may  even  be  supplied  at  a 
loss. 

Occasionally  the  charges  are  based  on  the  rental,  more 
frequently  on  the  rateable  value.  The  rateable  value  is 
very  variable,  and  consequently  where  the  assessments  are 
low  the  rates  will  be  correspondingly  high,  and  vice 
versa. 

For  domestic  purposes  water  is  almost  invariably 
charged  at  so  much  per  centum  on  the  annual  or  rate- 
able value;  for  other  purposes  the  supply  is  usually  by 
meter.  Where  the  owners  of  cottage  property  pay  the 
rate  whether  the  cottages  are  occupied  or  not,  a  reduction 
of  from  10  per  cent,  to  30  per  cent,  is  generally  made. 

Meters  are  almost  invariably  supplied  by  the  Water 
Authority  and  an  annual  rental  (10  per  cent,  on  cost) 
charged. 

It  is  difficult  to  define  "  domestic  purposes,"  but  Sec. 
12  of  the  26  and  27  Viet.,  cap.  93,  enacts  as  follows:  "A 
supply  of  water  for  domestic  purposes  shall  not  include 

(484) 


WATER  CHARGES  485 

a  supply  of  water  for  cattle  or  for  horses,  or  for  washing 
carriages,  where  such  horses  or  carriages  are  kept  for  sale 
or  hire,  or  by  a  common  carrier,  or  a  supply  for  any  trade, 
manufacture  or  business,  or  for  watering  gardens,  or  for 
fountains  or  for  any  ornamental  purpose.  "  In  many 
private  Acts  there  are  still  more  extended  definitions  of 
what  "  domestic  purposes  "  does  not  include. 

Generally  water  to  one  water-closet  is  included  in  the 
rate ;  extra  closets  being  charged  at  from  5s.  to  10s.  per 
annum. 

One  bath  may  be  allowed  and  others  charged  extra,  or 
a  single  bath  may  be  an  extra.  There  is  also  generally  a 
stipulation  that  if  the  bath  holds,  when  filled  for  use, 
more  than  a  given  amount,  usually  40  or  50  gallons,  a 
further  charge  is  made. 

I  have  recently  had  occasion  to  prepare  for  the  Essex 
County  Council  a  list  of  the  charges  made  by  all  the 
Water  Authorities  in  that  county,  and  these  are  briefly 
summarised  in  the  subjoined  table. 

The  following  typical  scales  are  given  in  full :  — 

EAST  LONDON  WATERWORKS  AREA  OF  SUPPLY. 

The  East  London  Company  have  two  scales  of  charges, 
one  for  the  Metropolitan  area  and  one  for  districts  out- 
side the  metropolis. 

In  the  Metropolitan  area  the  basis  is  the  Rateable  Value, 
outside  the  Metropolis  it  is  the  Net  Annual  Value.  Other- 
wise the  figures  in  the  two  scales  are  identical. 

Outside  the  Metropolis. 

High  Service, 

Net  Annual  Value.       *§£*£     Baths.       Water  Closets.     %£SftSSX 

the  Pavement. 

Not  exceeding    £30        5        4s.  each  Nil.         "j 

Exceeding  £30        5        4s.     ,,  4s.  each      1 25  per  cent. 

„  £50        5        6s.     „  6s.     „  in  addition. 

£100        5        8s.     „ 


486  WATER  SUPPLIES 

The  basis  to  be  adopted  will  be  that  laid  down  in  the 
judgment  of  the  House  of  Lords,  namely,  "  The  rent  at 
which  the  property  would  let,  deducting  the  probable 
average  annual  cost  of  repairs,  insurance,  and  other  ex- 
penses (if  any)  necessary  to  maintain  the  premises  in  a 
state  to  command  such  rent."  (Such  deductions  amount 
generally  to  about  10  per  cent.)  To  remove  misappre- 
hension consumers  are  informed  that  the  "  Parish  Assess- 
ment "  is  not  imposed  as  the  basis,  and  the  directors  cannot 
accept  it. 

The  following  uses  are  not  included  in  the  charge  :  — 

Steam  engines,  warming,  ventilating  machines,  appara- 
tus, horses,  cattle,  washing  carriages,  gardens,  fountains, 
ornamental  purposes,  flushing  sewers  or  drains,  or  for 
any  trade,  manufacture,  business  or  pursuit  requiring  an 
extra  supply  of  water.  With  regard  to  trade  purposes  a 
charge  is  mad©  according  to  a  scale  laid  down  in  the 
Company's  Act  which  varies,  according  to  the  quantity  of 
water  taken,  from  9d.  to  6d.  per  1000  gallons. 

Terms  of  supply  for  any  of  these  purposes  to  be  a 
matter  of  agreement.  No  charge  is  fixed  by  the  Act. 

The  owners  of  tenements  not  exceeding  the  "  annual 
value  "  of  £20  shall  be  liable  for  payment  of  rates  instead 
of  occupiers  upon  the  same  scale.  See  Section  81,  East 
London  Water  Company's  Act,  1853. 

BOBOUGH  OF   COLCHESTER. 

i 
For  Domestic  Purposes. 

Per  Annum. 

£     S.       D. 

Where    the    annual    rackrent    or  value    of    the 
premises  so  supplied  does  not  exceed  £5  per 

annum •.         .         .  070 

Exceeding  £5  and  not  exceeding  £10  per  annum  0  10    0 

£10            „                       £15         „  0  15    0 

£15            „                      £20        „  100 

£20            „                       £25         „  150 

£25            „                       £30        „  1  10    0 

£30                                     £40  200 


WATER  CHARGES  487 

Where  above  £40,  at  a  rate  not  exceeding  £5  per  cent,  per 
annum  of  such  annual  rackrent  or  gross  value. 

Note. — A  supply  of  water  for  domestic  purposes  does 
not  include  a  supply  for  more  than  one  water-closet,  or 
for  cattle,  or  for  horses,  or  for  washing  carriages  where 
such  horses  or  carriages  are  kept  for  sale  or  hire,  or  by 
a  common  carrier,  or  for  trade  or  business  purposes,  or 
where  the  same  are  kept  in  or  upon  premises  the  rent  of 
which  is  not  included  with  and  taken  as  part  of  that  of  a 
private  dwelling  house,  or  are  the  property  of  a  dealer;  or 
for  steam  engines ;  or  for  railway  purposes ;  or  for  working 
any  machine  or  apparatus;  or  for  any  trade,  manufacture, 
or  business  whatsoever ;  or  for  watering  gardens  by  means 
of  any  tap,  tube,  pipe,  sprinkler,  or  other  such  like  ap- 
paratus ;  or  for  flushing  sewers  or  drains ;  or  for  public 
baths ;  or  for  any  fixed  bath,  hydrant,  lavatory,  or  urinal ; 
or  for  any  ornamental  purpose  whatever. 

For  extra  water-closets,  each  per  annum,  5s. 
For  fixed  baths,  each  per  annum,  10s. 
For  urinals  and  lavatories,  by  arrangement. 
For  fountains,  by  meter  only. 


For  Gardens. 

If  a  hose  or  sprinkler  be  used,  the  water  to  be  taken 
by  meter  at  the  same  rate  as  is  charged  for  water  supplied 
for  trade  or  business  and  upon  the  samei  conditions. 

In  the  case  of  detached  or  market  gardens,  arrange- 
ments to  be  made  with  the  Superintendent. 

S,       D. 

For  one  horse  (where  chargeable)  2     6  per  qr. 

For  every  horse  above  one  „  16,, 

For  carriages,  each  ,,  16,, 

For  cows,  each 10,, 

For  pigs,  each 06,, 


488  WATER  SUPPLIES 

For  Building  Purposes. 

S.       D. 

On  entire  value  or  contract  price  of  work 

for  the  first  £1,000  or  part  of  £1,000      .         5     0  per  cent. 
For  the  second  £1,000  ....40,, 

For  the  third  and  each  subsequent  '£1,000  .         30         ,, 

For  slaughter-houses,  by  meter  only. 

Water  will  be  supplied  by  meter  by  special  arrangement. 

As  to  Supplies  by  Meter. 

If  water  is  supplied  by  meter,  it  will  be  by  special 
agreement  in  each  case. 

Where  water  is  supplied  by  meter  for  both  domestic 
and  other  purposes  a  minimum  charge  will  be  fixed  allow- 
ing the  consumption  of  a  certain  quantity  of  water.  All 
water  beyond  that  quantity  will  be  charged  for  as 
follows :  — 

Where  water  is  used  solely  for  trade  purposes  there  will 
be  no  minimum  charge. 

S.      D. 

Up  to  50,000  gallons  per  quarter 
beyond  the  quantity  allowed 
by  the  minimum  charge  .  .  1  2  per  1,000  gallons. 

Exceeding  50,000  and  not  exceed- 
ing 100,000  ....  1  1 

Exceeding  100,000  and  not  exceed- 
ing 150,000  ....  1  0 

Exceeding  150,000  and  not  exceed- 
ing 200,000  ....  0  11 

Exceeding  200,000  and  not  exceed- 
ing 250,000  ....  0  10 

Exceeding  250,000  and  not  exceed- 
ing 300,000  ....  0  9 

Exceeding  300,000  and  not  exceed- 
ing 500,000  ....  0  8  „ 

Exceeding  500,000  ....        0    7  „ 

The  Council  will  be  prepared  to  supply  and  keep  in 
repair  the  meter,  at  a  rent  in  accordance  with  the  follow- 
ing scale,  viz. ;  — 


WATER  CHARGES  489 


Size  of  Me 

§  inch 
4 

1          , 
1 

14 
2 
3 
4 

ter.                                                   Rate  per  Quarter. 

S.       D. 

bore       16 

1 

9 
6 
3 
3 
0 
3 
0 

2 

4 

5 

8 

11 
21 

In  addition  to  the  meter  rent  in  accordance  with  the 
above  scale,  the  consumer  must  bear  the  expense  of  all 
necessary  fittings  to,  and  the  fixing  of,  the  meter. 

MALDON   RURAL  ^  DISTRICT. 

On  Sept.  26th,  1900,  the  District  Water  Committee 
controlling  the  new  public  supply  to  Purleigh  and  other 
parishes,  resolved 

1.  That  a  charge  be  made  of  2d.  per  week  for  cottages, 
the  annual  value  of  which  is  £6  and  under,  for  the  use  of 
the  water. 

2.  Also  that  a  rate  of  Is.   6d.  in  the  £  for  12  months 
be  charged  on  houses,  the  annual  value  of  which  is  above 
£6. 

3.  Also  that  water  (other  than  for  domestic   purposes) 
should  be  supplied  by  meter,  and  that  consumers  requiring 
meters  must  provide  the  same,  but  obtain  them  from  the 
Council. 

4.  Also  that  where  water  is  taken  by  meter  a  minimum 
charge  of  10s.  per  quarter  be  made;    that  up  to  and  in- 
cluding 20,000  gallons  a  charge  of  Is.  3d.  per  1,000  gallons, 
and  above  that  quantity  a  charge  of  Is.  per  1,000  gallons 
be  made. 

5.  Also  that   a   minimum    charge   of   15s.    be   made   for 
taking  water  from  swan  neck  standposts,  from  the  present 
time  until  Christmas. 

6.  Also  that  owners  can  obtain  keys  of  standposts  from 


490 


WATER  SUPPLIES 


the  Engineer  at  their  own  expense,  for  the  use  of  each 
cottage,  and  that  in  cases  where  keys  have  already  been 
distributed,  the  charge  for  same  is  to  be  requested. 

In  Southminster  where  there  is  a  separate  public  supply 
the  water  rate  is  Is.  4d.  in  the  'pound  on  the  rateable 
value,  and  Is.  per  1,000  gallons  by  meter. 

CLACTON-ON-SEA    URBAN    DISTRICT. 

No.   1. 
Ordinary    Charges. 

Payable  quarterly  in  advance  by  owners  or  occupiers  of 
private  dwelling  houses  for  the  supply  of  water  for  domestic 
purposes  only  as  authorised  by  61  and  62  Viet.,  cap.  185. 


Houses  of  the  Annual 
Gross  Estimated 
Rental. 

Charges 
per  Quarter. 

£ 

s. 

D. 

£ 

s 

D. 

Not  exceeding     5 

0 

0 

0 

2 

2 

10 

0 

0 

0 

4 

0 

„              15 

0 

0 

0 

6 

0 

20 

0 

0 

0 

8 

0 

25 

0 

0 

0 

9 

9 

30 

0 

0 

0 

11 

6 

35 

0 

0 

0 

13 

3 

40 

0 

0 

0 

15 

0 

„              45 

0 

0 

0 

16 

6 

50 

0 

0 

0 

18 

0 

55 

0 

0 

0 

19 

6 

60 

0 

0 

1 

1 

0 

65 

0 

0 

1 

2 

3 

.       „              70 

0 

0 

1 

3 

6 

75 

0 

0 

1 

4 

9 

80 

0 

0 

1 

6 

0 

85 

0 

0 

1 

7 

0 

90 

0 

0 

1 

8 

0 

95 

0 

0 

1 

9 

0 

100 

0 

0 

1 

10 

0 

Where  such  gross  estimated  rental  shall  exceed  £100,  at 
a  rate  per  centum  not  exceeding  £5   10s.  per  annum. 


WATER  CHARGES  491 

Note. — A  supply  for  domestic  purposes  does  not  include 
a  supply  of  water  for  cattle,  or  for  horses,  or  for  washing 
carriages  where  such  horses  or  carriages  are  kept  for  sale 
or  hire,  or  by  a  common  carrier ;  nor  does  it  include  a 
supply  of  water  for  any  trade,  manufacture  or  business 
whatsoever,  or  for  watering  gardens,  or  for  fountains, 
greenhouses,  or  vineries,  njor  for  watering  roads  or  pave- 
ments, no>r  for  any  ornamental  purpose,  nor  for  the  purpose 
of  washing  the  fronts  or  windows  of  houses,  or  other  build- 
ings, by  means  of  any  gutta  percha,  india  rubber,  or  other 
tubes  or  pipes,  nor  for  any  of  the  special  purposes  for 
which  additional  charges  are  notified  in  the  Table  No.  2. 

Every  supply  for  domestic  purposes  includes  a  supply 
to  one  water-closet  free  of  charge ;  for  each  water-closet 
beyond  the  first  included  in  such  domestic  supply,  an 
additional  charge  of  Is.  lOJd.  per  closet  per  quarter  will  be 
made. 

Baths. — Each  supply  to  a  private  fixed  bath  will  be 
charged  the  additional  sum  of  2s.  6d.  per  quarter,  but  no 
bath  will  be  permitted  which  contains,  when  filled  for  use, 
more  than  50  gallons  of  water. 

Where  an  outbuilding  is  appurtenant  to,  or  taken  with, 
a  dwelling,  the  charge  for  water  will  be  on  the  aggregate 
annual  value  of  the  whole  premises,  and  no  deduction  will 
be  made  by  reason  of  any  portion  being  unoccupied. 

Terms  of  Payment. 

For  all  houses  of  or  under  the  value  of  £10  the  owners 
are  required  to  pay  for  the  supply  of  water,  61  and  62 
Viet.,  cap.  185. 

Owners  may  compound  for  groups  of  houses  of  the  above 
description  not  being  fewer  than  three  in  number,  and 
will  be  allowed  a  deduction  of  20  per  cent. ;  but  the 
owners  of  such  houses  will  have  to  pay  whether  such  houses 
be  occupied  or  not. 

All  rates,  additional  charges,  charges  under  agreements, 
and  rents  of  meters  are  payable  quarterly  in  advance  and 


492  WATER  SUPPLIES 

accrue  due  at  the  usual  quarter-day,  viz.  :  Christmas  Day, 
Lady  Day,  Midsummer  Day,  and  Michaelmas  Day. 

The  first  payment  becomes  due  at  the  time  when  the 
pipe  by  which  the  water  is  supplied  is  made  to  communi- 
cate with  the  consumer's  pipes,  or  at  the  time  when  the 
agreement  to  take  water  from  the  Council  is  made. 

The  Council  reserve  to  themselves  the  right  of  modify- 
ing the  above  stipulations  in  favour  of  the  consumer.  In 
all  cases  notice  in  writing  will  be  required  from  those 
intending  to  discontinue  taking  a  supply  of  water ;  and 
should  this  notice  be  given  at  any  other  time  than  on  one 
of  the  abov»-mentioiied  quarter-days,  or  in  t/he  absence  of 
such  notice,  the  consumer  must  pay  the  full  rates  and 
charges  up  to  quarter-day  next  ensuing  after  the  date  upon 
which  such  notice  is  given,  or  upon  which  such  discon- 
tinuation of  supply  took  effect  (10  and  11  Viet.,  cap.  17). 

No.    2. 
Additional     Charges. 

Payable  quarterly  for  supply  of  water  for  the  following 
special  purpose,  viz.  :  — 

Per  Quarter. 

S.      D. 

Carriages  with  2  wheels        .         ...         .        .         .  20 

4  .         .        '-.-'      .        .         .  30 

Horses,  each          .         .         .         ....         .  26 

Cows,  not  exceeding  2  .         ....        .         .         .  30 

4  ......  5    6 

6  ......  8    0 

Laundresses,  upwards  from          .        -.        .         .         .  26 

Butchers        .         .         .         .         .        .         .      ".         .  3     0 

Bakers  ...;..,..  3     0 

Fishmongers 30 

Gardens  attached  to  a  house  and  included  in  the  gross 

estimated  rental,  if  watered  by  hose,  to  be  charged 

by  meter. 

Lock-up  shops,  offices  and  warehouses,  by  agreement. 
Lock-up  shops,  offices  and  warehouses  will  be  charged 

in  addition  for  each  water-closet  .         .         .         .  16 

Urinals          .......         t         .  1  10 


WATER  CHARGES  493 

All   other  purposes  not  particularly  named  herein  to  be 
charged  by  special  agreement. 

No.    3. 
Meter     Supplies. 

(Allowed  only  in  special  cases,  and  at  the  option  of 
the  Council.) 

Charges  for  Water  delivered  through  Meter. 

For  trade  and  special  purposes,  payable  quarterly,  at 
the  following  rates;  a  minimum  quantity  of  10,000  gallons 
per  quarter  being  charged  for  in  any  case :  — 

Quantity  used  per  Quarter.  Gallons.  i^iw  Gals. 

S.      D. 

For  the  first       ....  50,000  and  under  2  3 

For  the  quantity  from      .         .  50,000  to  100,000  2  0 

,    ^       .         100,000  to  150,000  1  9 

above    .         .         150,000  1  6 

Larger  quantities  by  special  agreement. 

Hire    of    Meters. 

The  Council  will  provide,  fix  and  maintain  the  meters, 
charging  a  quarterly  rent  for  their  use  according  to  size  of 
meter,  viz.  :  — 

s.    D.  s.    D. 

For  a  §  in.  meter     .         1     6  For  a  1J  in.  meter   .         3     0 

»     4                      .16  „     1J                    .36 

„     I                      .20  ,,2          ,,.46 
1                               26 


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GENERAL  INDEX. 


ABYSSINIAN  tube  wells,  369. 

yield  of,  370,  372,  375. 
„  „          cost  of,  373. 

Acid  waters,  9,  362. 
Action  of  frost  on  water  mains,  440. 

,,       of  water  on  metals,  8. 
Adits,  353. 
Advantages  of  softened  waters,  127. 

,,  underground  sources  of  water,  82. 

Alum,  clarification  by,  286. 
Amount  of  nitrates  in  chalk  and  other  water,  185. 

water  available,  factors  influencing  the,  95. 
raised  by  pumps,  398,  402. 
required  for  domestic  and  other  purposes,  305. 
used,  constant  supply,  308,  434. 
„      by  cattle,  317. 
,,      intermittent  supply,  308. 
„       in  tropical  climates,  317. 
Analyses,  vide  Tables. 

interpretation  of,  178. 
ammonia,  188. 
chlorine,  179. 
nitrates,  183. 
nitrites,  184. 
organic  ammonia,  191. 

„       carbon  and  nitrogen,  190. 
oxygen  absorbed,  193. 
phosphates,  189. 
well  waters,  56,  58,  88,  89. 
Analysis,  systematic,  354,  355,  357. 
Animal  charcoal,  properties  of,  284. 

„       parasites,  diseases  due  to,  171. 
Animals,  effect  of  polluted  water  upon,  175. 
Annual  water  charges,  494,  495. 
Aqueducts,  fall  of,  435. 
Area  of  filter  beds,  266,  267. 
Artesian  wells,  74,  378,  383,  384,  386. 
Asterionella,  114.    ' 
Atmosphere,  moisture  in,  14. 

(499) 


500  GENERAL  INDEX 

BACTERIA  in  water,  120,  204. 

effect  of  sunlight  upon,  250-358. 

,,  ,,        sedimentation  upon,  247. 

„         removed  by  sand  nitration,  257. 
Bacteriological  examination  of  water,  204. 
Ball  hydrants,  dangers  of,  238-240. 
Beggiatoa  alba,  117. 
Blasting  of  deep  wells,  385. 
Bogs,  marshes  and  swamps,  45. 
Boiling-point  of  water,  5. 
Boils,  oriental,  171. 
Bored  tube  wells,  355. 
Bore-tube,  advantages  and  disadvantages  of  pumping  from,  375. 

,,          varieties  of,  378. 
Boring  wells,  cost  of,  380. 
Brine  yielded  by  well,  340. 
Burial  of  carcases,  pollution  by,  227. 
Bursaria  gastris,  113. 

CARBONIC  acid  in  water,  6. 
Cast-iron  mains,  437. 

,,  ,,       acted  upon  by  soft  water,  233. 

Catchment  basins,  90,  331. 
Cattle,  amount  of  water  used  by,  317. 

,,       pollution  by,  227. 
Causes  of  rain,  15. 

„         waste  of  water,  313. 

Cesspools  and  house  drainage,  pollution  by,  219,  222,  226. 
Chalk,  water  held  by,  48,  78,  335,  350. 
Chara  foetida,  116. 
Character  of  water  from  springs,  69. 
Charcoal,  animal  properties  of,  214. 

,,        vegetable  properties  of,  284. 
Chlorine  in  surface  waters,  34. 

„        signification  of,  179. 
Cholera,  164. 

„        and  defective  filters,  170. 

and  improved  water  supplies,  166,  357. 

and  water  filtration,  214,  215. 

death-rate,  effect  of  changed  water  supply  upon,  167. 

organisms,  influence  of  soil  on,  368. 

outbreaks  of,  Altona,  168,  206,  257,  260. 

Hamburg,  168,  206. 
,,  London,  165. 

Poonah  Jail,  168. 
„  „  Theydon  Bois,  167. 

„  „  Vadakencoulam,  168. 

Wandsbeck,  168. 
Cisterns,  action  of  water  on,  231. 
,,        galvanised  iron,  232. 
„        house,  230,  434. 


GENERAL  INDEX  50! 


Cisterns,  rain-water,  24. 
zinc,  232,  234. 

Clarification  of  water  by  alum,  280. 
Classification  of  mineral  waters,  13. 
,,  of  odours  of  water,  112. 

„  of  potable  waters,  13,  30. 

Cleansing  of  filter  beds,  265,  268. 
Coal  gas,  pollution  by,  228. 
Collecting  areas,  342,  359. 

,,          channels,  353. 
Collection  of  rain-water,  28. 
Colour  of  water,  2,  110. 

,,      removal  by  filtration,  263. 
Communication  pipes,  436. 
Composition  of  water,  1. 
Conduits,  open,  435. 
Conferva  Bombycina,  115. 
Constant  supply,  308,  434. 
Constituents  of  natural  waters,  7,  123. 
Construction  of  filt'er  beds,  264,  274. 

of  wells,  364. 
Consumption  of  water,  daily  variation  in,  317. 

,,  ,,         hourly  variation  in,  310,  429. 

Control  of  gathering  ground,  359,  361. 
Cost  of  public  water  supplies,  38,  40. 

boring  wells,  380. 
„       softening  hard  water,  289,  294,  300,  302. 

tube  wells,  373. 
,,       well  sinking,  373. 
Cottage  filters,  283. 
Crenothrix,  114,  429. 
Cryptomonas,  114. 
Cultivated  land,  pollution  from,  219. 

DAIRY  farms,  450. 

Dead  animals,  odour  of  water  caused  by,  118. 

„     ends,  438. 

Decomposing  animals  in  water,  diarrhoea  due  to,  136. 
Decomposition  of  water  by  electricity,  1. 
Deep-well  water,  30,  74,  84,  336,  362. 

,,  ,,      pollution  of,  80,  228. 

Deep  wells,  blasting  of,  385. 

boring  of,  379. 

cost  of,  380. 

effect  of  pumping  on,  82,  351. 

increased  supply  by  blasting,  385. 

pollution  of,  80,  228. 

protection  of,  355,  356. 

site,  selection  of,  81. 

yield  of,  84,  86,  337,  386. 
Defective  filters  and  cholera,  170. 


502  GENERAL  INDEX 

Defective  mains,  149,  240. 

Density  of  water,  4. 

Depth  of  mains,  437. 

Description  of  public  water  supplies,  37,  39,  473. 

Deserts,  17. 

Detection  of  waste  of  water,  313. 

Diameter  of  mains,  436. 

Diarrhoaa,  133. 

due  to  distilled  water,  286. 

„  ,,      decomposing  animals  in  water,  136. 

„  ,,      sewage  in  water,  135. 

,,  ,,      sewer  gas  in  water,  134. 

,,  „      sulphuretted  water,  134. 

„      turbid  river  water,  134,  135. 
Direction  of  flow  of  underground  water,  353. 
Diseases  due  to  animal  parasites,  171. 
„  ,,      specific  organisms,  142. 

„          parasitic,  171. 
Discharge  of  water  from  pipes,  417. 
Distillation  of  water,  14,  280,  289. 

,,  sea-water,  280. 

Distilled  water,  diarrhoea  due  to,  286. 
Distributing  mains,  436. 
Distribution  of  water,  434. 

pollution  of  water  during,  233,  238. 
Divining  rod,  324. 

Domestic  and  other  purposes,  amount  of  water  required,  305. 
,,         consumption  of  water,  310. 
filters,  278. 

dangers  of,  282. 
high  pressure,  278. 
limited  utility  of,  282. 
low  pressure,  278. 
self -supplying,  281. 
„         purification  of  water,  278. 
Drainage  area,  331. 

„     of  deep  wells,  48,  323. 
„     of  shallow  wells,  48,  328. 
Drinking  water,  qualities  of,  109. 

„       typhoid  bacilli  in,  206,  207,  214. 
Dual  supply,  341. 

Dust,  exposure  to,  pollution  by;  241. 

Duties  of  sanitary  authority  as  regards  water  supply,  463. 
Dysentery,  outbreaks  due  to  impure  water,  136,  203. 

EARTH,  living,  action  of,  51. 
Eels  in  water  mains,  118. 
Effect  of  scraping  filter  beds,  258. 
Efficiency  of  filtration,  255,  261. 

,,        of  pumps,  399. 
Electricity,  decomposition  of  water  by,  1. 


GENERAL  INDEX 


503 


Engines,  pumping,  gas,  415. 
oil,  414. 
steam,  415. 
water,  405. 
wind,  402. 


Enteric  fever 


vide  Typhoid  fever. 


Entoza,  affecting  man,  172. 
Estimation  of  rainfall,  20. 
Evaporation,  loss  of  water  by,  332. 

rate  of,  14. 

,,  „      from  the  ocean,  15. 

Examination  of  water,  bacteriological,  204. 
Expansion  of  water  when  freezing,  4. 
Exposed  reservoirs,  effect  of  temperature  on  water  in,  428. 

FACTORS  influencing  amount  of  water  available,  95. 
Farmyards,  pollution  from,  151,  219,  223. 
Ferrule  machine,  438. 
Filter-beds,  264,  271. 

„  action  of  slime  on,  260. 

area  of,  266. 

„       to  calculate,  267. 
cleansing  of,  265,  268. 
construction  of,  264,  274. 
effect  of  scraping,  258. 
polarite,  271,  284. 
Filters,  cottage,  283. 
domestic,  278. 

,,          high  pressure,  278. 

limited  utility  of,  282. 
,,          low  pressure,  278. 
„         self-supplying,  281. 
Filtration  and  cholera,  214,  215. 
at  Altona,  260. 
by  machinery,  269. 
efficiency  of,  255,  261,  360,  361. 
natural,  343,  348. 

„       testing  of,  347. 
nitrification  during,  263. 
of  rain  water,  28. 
rapidity  of,  262. 
removal  of  colour  by,  263. 

„          typhoid  bacilli  by,  256. 
sand,  362. 
Finding  water,  324. 
Fire  extinction,  water  reserve  for,  430. 
Fissured  strata,  351,  354. 
Flow  of  river,  purification  by,  242. 

„      underground  water,  direction  of  flow  of,  353. 
„       water  over  notched  boards,  323. 
,,  ,,     through  mains,  436. 


504  GENERAL  INDEX 

Force  required  to  work  pumps,  401. 

Formation  of  springs,  46,  47,  61. 

Formulae,  Pole's,  for  yield  of  catchment  area,  332. 

„         Hawksley's,  storage,  334. 

„         Eytelwein's,  for  velocity,  435. 

„         Burton's,  for  fire  reserve,  430. 
Freezing,  expansion  of  water  when,  4. 

,,         point  of  water,  3. 
Friction,  loss  of  head  by,  436. 
Frost,  action  on  mains,  440. 
Fungi,  higher,  in  water,  122. 

GALVANISED  iron  cisterns,  232. 

Gas  engines,  415. 

Gathering  ground,  control  of,  359,  361. 

Gauging  of  springs  and  streams,  100,  322. 

wells,  327. 
Goitre,  137. 

„       alleged  causes  of,  138. 

,,       localities  in  which  prevalent,  138. 
Granite,  water  held  by,  48. 
Gravel,  pocket  of,  46. 
Graveyards,  pollution  from,  227. 
Gravitation  works,  425. 
Ground  water,  vide  Subsoil  water. 

HARD  water,  7. 

cost  of  softening,  289,  294,  300,  302. 
„  influence  on  health  of,  124 

,,  softening  processes,  288. 

,,  waste  caused  by,  127. 

Hazel  twig,  effect  of  water  upon,  324. 
Head  of  water,  268. 

,,     loss  by  friction,  436. 
Health,  effect  of  impure  water  upon,  .133. 

,,        effect  of  zinc  upon.  236. 
"Health"  pipe,  141,  439. 
Heat,  latent,  of  water,  3. 
Hemp  stuffing,  fouling  of  water  by,  233. 
High-pressure  filters,  278. 
Horse-power,  definition  of,  417. 

,,  equivalent  in  water  raised,  418. 

Hourly  consumption,  inequality  of,  429. 

„       variation  in  supply,  310. 
House  cisterns,  230,  434. 

,,       drainage  and  cesspools,  pollution  by,  219,  222,  226. 
,,      service  mains,  436,  439. 
Hydrants,  ball,  dangers  of,  238. 
Hydraulic  rams,  406. 

,,  efficiency  of,  408. 


GENERAL  INDEX  565 

IMBIBITION,  46. 
Impervious  strata,  45. 
Impounding  reservoirs,  289,  423. 
Improved  water  supplies,  cholera  and,  166,  357. 
Impure  water,  dysentery  owing  to,  136,  203. 
,,  effect  upon  animals,  175. 

health,  133. 

,,  saline  constituents  of,  132. 

Impurities  in  rain  water,  22. 

,,         metallic,  in  water,  8,  12,  139,  236. 
Incompressibility  of  water,  2. 
Inequality  of  hourly  consumption,  310,  429. 
Influence  of  rain  on  well  water,  354. 

,,       of  soil  on  cholera  and  typhoid  organisms,  368. 

„       on  health  of  hard  water,  124. 

„       on  infusoria,  251. 
Insuction  at  water  joints,  238. 
of  filth  by  mains,  238. 

„  subsoil  water,  356. 

Interlacing  system  of  mains,  438. 
Intermittent  pollution,  194,  215. 

,,  supply,  dangers  of,  238. 

„  ,,       to  various  towns,  308,  434. 

Interpretation  of  water  analyses,  178. 
Iron  in  water,  8,  12. 
Isolated  houses,  supply  for,  320. 
Is  water  analysis  a  failure  ?  194. 

JOINTS  of  water  mains,  437. 

,,      fouling  of  water,  by  hemp  stuffing,  233. 
„      insuction  at,  238. 

LAKES,  36. 

,,       as  reservoirs,  35. 
Land  and  water  rights,  purchase  of,  447. 
Latent  heat  of  water,  3. 
Laws  relating  to  rural  water  supplies,  447. 

rivers  and  water-courses,  449,  450. 
springs,  449,  450. 
subsoil  water,  449,  452. 
water  supplies,  447. 
Lands  Clauses  Consolidation  Acts,  447. 
Limited  Owners  Reservoir,  etc.,  Act,  464. 
Public  Health  Act,  447,  458,  460,  462. 
Public  Health  (Scotland)  Act,  468. 
Public  Health  (Water)  Act,  447,  458,  462,  470. 
Settled  Land  Act,  448. 
Waterworks  Clauses  Acts,  458,  460. 
Cases — 

Borough  of  Bradford  v.  Pickles,  454. 
Broadbent  v.  Ramsbottom,  452. 


506  GENERAL  INDEX 

Cases  (continued) : — 

Chasemore  v.  Richards,  453. 
Dudden  v.  Guardians,  Glutton  Union,  450. 
Embrey  v.  Owen,  451. 
Holmfirth  Local  Board  v.  Shore,  466. 
Jordeson  v.  Button,  Southcoats  and  Dryport  Gas  Co.,  456. 
Milner  v.  Gilmour,  451. 
Pogglewell  v.  Hodkinson,  457. 
Smith  v.  Archibald,  468. 

Swindon  Water  Co.  v.  Wilts  and  Berks  Canal,  452. 
Wandsworth  Board  of  Works  v.  United  Telephone  Co.,  467. 
Lead  cisterns,  140,  232. 
„     in  water,  8,  12,  24,  140. 
„     pipes,  234. 
,,     poisoning,  8,  139. 

symptoms  of,  139,  235. 

Legal  decisions  affecting  water  supplies,  450. 
Lime,  softening  of  water  by  the  addition  of,  289. 
Limestone,  water  held  by,  48,  78. 
Limited  Owners  Reservoirs  andWater  SupplyFurther  Facilities  Act,464. 

utility  of  niters,  282. 
Living  earth,  action  of,  51. 
Loss  of  head  by  friction,  436. 
„     of  water  by  evaporation,  332,  333. 

„  ,,  ,,  percolation,  333. 

Low  forms  of  animal  and  vegetable  life  in  water,  122. 

„     pressure  niters,  278. 
Lyngbya  muralis,  117. 

MACHINERY,  nitration  by,  269. 
Magnesia,  sulphate  of,  337. 
Magnetic  carbide,  273. 
Mains,  action  of  frost  on,  440. 

cast-iron,  437. 

dead  ends,  438. 

depth  of,  437,  440. 

diameter  of,  436. 

distributing,  437. 

eels  in,  118. 

flow  of  water  through,  436. 

house  service,  436,  439. 

insuction  of  filth  by,  238. 

interlacing  system  of,  438. 

joints  of,  437. 

trunk,  436. 

velocity  of  water  in,  435. 
Malaria,  143. 

decrease  in  England,  143. 
outbreak  on  board  ship,  144. 
„        where  prevalent,  143. 
Marshes,  swamp  and  bogs,  45. 


GENERAL  INDEX  507 

Maximum  consumption  of  water,  429. 

,,          density  of  water,  4. 

„          rainfall,  96. 
Mean  consumption  of  water,  429. 
Metallic  impurities  in  water,  8,  12,  139,  236. 
Metals,  action  of  water  on,  8. 
Methods,  special,  of  tracing  pollution,  151,  204. 
Metropolis  Act,  440. 
Metropolitan  Water  Supply,  Royal  Commission  Report  on,  76,  92,  93, 

98,  195,  265,  311. 

Mineral  waters,  classification  of,  13. 
Minimum  rainfall,  96. 
Moisture  in  atmosphere,  14. 
Moorland  waters,  9,  30. 
Movements  of  subsoil  water,  48,  225. 

NATURAL  reservoirs,  427. 

,,         water,  constituents  of,  7,  123. 
,,  „      classification  of,  13,  30. 

Nitrates  and  nitrites,  183,  184. 

„  ,,         how  formed,  222. 

,,  ,,         in  chalk  waters,  185. 

„  ,,         reduction  of,  187. 

,,  ,,         signification  of,  183. 

Nitrification  during  filtration,  263. 
process  of,  222,  344. 
purification  by,  52,  221,  263. 

Nitrogen,  organic,  190.  ¥ 

Nitrogenous  organic  matter,  191. 
Nostoc,  115. 

ODOUR  of  water,  2,  111,  361. 

„       caused  by  Asterionella,  114. 

Beggiatoa  alba,  117. 
Bursaria  gastris,  113. 
Chara  fcetida,  107,  115,  116. 
Conferva  Bombycina,  115. 
Crenothrix,  114,  189,  429. 
Cryptomonas,  114. 
Lyngbya  muralis,  117. 
Nostoc,  115. 
Oscillatorise,  116. 
Spongilla  fluviatilis,  113. 
Tabellaria,  114. 
Uroglena  Americana,  113. 
Volvox  globator,  113. 
due  to  dead  animals,  118. 
„      hemp  joints,  233. 
,,      sulphuretted  hydrogen,  111. 
„  ,,      tar  varnish,  437. 

Odours  of  water,  classification  of,  112. 


5o8  GENERAL  INDEX 

Oil  engines,  414. 

Oolite,  water  held  by,  48,  78,  336. 

Open  conduits,  435. 

Organic  ammonia,  191. 

,,        carbon  and  nitrogen.  190. 
„        matter  in  water,  7,  190. 
Organisms  in  water,  120. 

Bacteria,  121,  204. 

Higher  fungi,  122. 

Low  forms  of  animal  and  vegetable  life,  122. 
Oriental  boils,  171. 
Origin  of  rivers,  90. 
Oscillatorise,  116. 
Oxidation  by  air,  358. 

,,          in  running  water,  244,  344. 
Oxidising  effects  produced  by  sand  filtration,  263. 
Oxygen  absorbed  by  water,  193. 
in  water,  6,  244,  246. 

PALATABILITY  of  water,  119. 
Parasitic  diseases,  171. 
Parish  Councils  and  water  supplies,  460. 
Peaty  water,  10,  32. 

,,  effect  of  storage  on,  427. 

Pebble  beds,  water  held  by,  48. 
Percolation,  45,  49. 

„  loss  by,  333. 

Periodic  examination  of  public  supplies,  357,  362,  363. 
Permanganate  of  potash,  purification  by,  286. 
Permeability  of  subsoil,  45. 
Pervious  strata,  45. 
Phosphates  in  water,  189. 
Pipes,  action  of  water  on,  233. 

,,      communication,  436. 
Plumbo-solvent  action  of  water,  8,  11,  362. 

how  prevented,  12,  235. 
Pockets  of  gravel,  46. 
Polarite  filter  beds,  271,  273,  284. 
Pole's  formulae  for  yield  of  catchment  area,  332. 
Polluted  water,  effect  on  health,  133. 

,,  ,,      effect  on  animals,  175. 

Pollution  of  deep-well  water,  80,  228. 
rain-water,  23,  219,  361. 
rivers,  91,  219. 
subsoil  water,  52,  221. 
surface  water,  219. 
water  at  its  source,  219. 

„      during  distribution,  233,  238. 
„  „       storage,  229,  241. 

owing  to  sewage,  135,  136,  146,  149. 
,,        sewer  gas,  134. 


GENERAL  INDEX 


509 


Pollution  owing  to  sulphuretted  hydrogen,  134. 
„  ,,        surface  water,  136. 

,,  ,,        suspended  mineral  matters,  133. 

„        sources  of,  action  of  water  on  cisterns  and  tanks,  231. 

„  „          pipes,  233. 

burial  of  carcases,  227. 
cattle,  227. 

cesspools  and  house  drainage,  219,  222,  226. 
coal  gas,  228. 
cultivated  land,  219. 
exposure  to  dust,  241. 
farmyards,  151,  219,  223. 
graveyards,  227. 
insuction  through  ball-hydrants,  238,  240. 

defective  mains,  149,  240. 
stool  taps,  148,  238. 
sewage,  195. 
sewer  gas,  6,  134. 
snow,  melted,  230. 
sulphuretted  hydrogen,  134. 
tar  varnish,  437. 
tow  joints,  233. 
washings  from  roof,  219. 
Pollution,  special  methods  of  tracing,  151,  204. 

of  rivers,  Royal  Commission  on,  30,  44,  71,  73,  78,  92,  124, 

166,  183,  185,  188,  190,  233,  236,  288,  307,  316. 
Ponds,  35. 
Potable  water,  definition  of,  128. 

„  classification  of,  13,  30. 

Prevention  of  waste  of  water,  313,  316,  438. 
Previous  sewage  contamination,  185. 
Protection  of  surface  water  supplies,  358. 

„  underground  water  supplies,  342. 

Protective  area  round  springs,  352. 

„      wells,  353,  355,  356. 
Public  Health  Act,  447,  458,  460,  465. 
Public  Health  (Scotland)  Act,  468. 
Public  Health  Water  Act,  447,  458,  461,  470. 
,,      water  supplies,  cost  of,  38,  40,  474  to  483. 
,,  ,,  ,,          description  of,  473  to  484. 

„       wells,  England  and  Scotland,  466,  468. 
Pumping,  effect  on  deep  wells,  82,  351. 

from  bore  tube,  356,  375. 
,,          mains,  velocity  of  water  in,  435. 
Pumps,  amount  of  water  raised  by,  398. 
,,       and  pumping  machinery,  392,  400. 
„       efficiency  of,  399. 
,,       varieties  of,  392. 
Purchase  of  land  and  water  rights,  447. 
Pure  water,  definition  of,  2. 

„      ,,       saline  constitutents  of,  129. 


510 


GENERAL  INDEX 


Purification  of  waters  by  alum,  286. 

fermentation,  286. 

filtration,  256. 

flow  of  river,  242. 

nitrification,  52,  221,  263. 

permanganate  of  potash,  286. 

sedimentation,  253,  255. 

softening  process,  303. 

domestic,  278. 

Koch's  remarks  on,  260. 

Massachusetts,  experiments  on,  256. 
Purity,  standards  of,  215. 
Purposes  for  which  water  is  required,  306. 

QUALITY  of  drinking  water,  109. 

Quantity  of  water  obtainable  from  different  sources,  330. 

required  for  domestic  and  other  purposes,  305. 
supplied  by  various  London  companies,  311. 

in  different  towns,  309,  312. 
.used  by  cattle,  317. 

,,     in  towns  with  constant  supply,  308. 
„  ,,  intermittent  supply,  308. 

,,      tropical  climates,  317. 
yielded  by  artesian  wells,  383,  384,  386. 
tube  wells,  371,  372. 

RAIN-BEARING  winds,  16. 
Rain,  causes  of,  15. 
Rainfall,  16,  17,  37,  96,  342. 
at  Equator,  17. 

at  Kew,  Greenwich,  Massachusetts,  18. 
available  supply  of  water  from,  28,  329. 
collected  by  rivers,  96. 
how  estimated,  20. 
in  gallons  per  acre,  22. 
Rain-gauge,  19. 

,,  mountain,  20. 

,,  position,  19. 

Rain  water,  14,  22. 

„  action  on  lead,  24. 

„  cisterns,  23,  24. 

„  collection  of,  28. 

„  filtration  of,  28. 

how  polluted,  22,  219,  361. 
,,  impurities  in,  22. 

,,  separator,  26. 

storage  of,  24,  29,  432. 
Ram,  hydraulic,  406,  408. 
Rapidity  of  filtration,  262. 
Rate  of  evaporation,  14,  15. 
Regulations  under  Metropolis  Act,  440. 


GENERAL  INDEX  511 

Eemoval  of  colour  by  filtration,  263. 
Reserve  for  fire  extinction,  430. 
Reservoirs,  35,  358,  431. 

,,          impounding,  419. 

„          lakes  as,  35. 

„          natural,  427. 

„          service,  424,  427. 

settling,  423. 
Revolving  purifier,  272. 
River  water,  30,  90,  342. 

,,  revolving  purifier,  272. 

,,  suitability  of,  for  public  supplies,  94,  247. 

,,  towns  supplied  by,  106. 

Rivers  and  watercourses,  amount  of  water  available  from,  96. 

,,  „  laws  relating  to,  449,  450. 

,,  „  origin  of,  90. 

„  „  percentage  of  rainfall  collected  in,  97. 

„  ,,  pollution  of,  91. 

M  „  pollution,  Royal  Commission  on,  30,  44,  71, 

73,  78,  92,  124,  166,  183,  185,  188,  190, 
233,  236,  288,  307,  316. 

„  „  rainfall  collected  by,  96. 

„  „  self-purification  of,  92,  242. 

,,  ,,  subterranean,  50. 

,,  ,,  velocity  of  flow,  100. 

Rock,  saturation  of,  46. 
Roofs,  water  collected  from,  26. 
Running  water,  oxidation  in,  244,  344. 
Rural  water  supplies,  469. 

„  „         law  relating  to,  447. 

SALINE  constituents  of  impure  water,  132. 

,,  ,,  pure  water,  129. 

Sand  filtration,  362. 

„  ,,         experiments  on,  256. 

,,  ,,         oxidising  effects  produced  by,  263. 

,,  ,,         requisites  for  efficiency,  259,  260,  258. 

„     washing,  265,  275. 
Sandstone,  water  held  by,  48,  78,  336. 
Sanitary  Authority,  duties  of,  to  supply  water,  463. 
Saturation  of  rock,  46. 

Saving  effected  by  softening  water,  294,  303. 
Scale  of  purity,  211. 
Scrubbers,  269. 

Sea-water,  distillation  of,  280,  286. 
,,          for  sewer  flushing,  109. 
Search  for  water,  324. 
Sedimentation,  247,  358,  360. 
Selection  of  source  of  supply,  319. 
Self-purification  of  rivers,  92,  242. 

„  „  effect  of  bacteria,  250, 


512 


GENERAL  INDEX 


Self-purification,  effect  of  infusoria,  251. 
,,  ,,  ,,         oxidation,  246. 

,,  ,,  „         sedimentation,  247. 

„  ,,  „        sunlight,  250. 

Self-supplying  filters,  281. 
Separator,  rain-water,  26. 
Service  pipes,  439,  442. 

,,  ,,      unsuitable,  321. 

„       reservoirs,  424,  427. 
Settled  Land  Act,  448. 
Settling  reservoirs,  423. 
Sewage  in  water,  diarrhea  due  to,  135. 

pollution  by,  135,  136,  146,  149,  220. 
Sewer  gas,  pollution  by,  6,  134. 
Shallow  wells,  50,  343,  362. 

„  pollution  of,  223,  345. 

Site  of  deep  wells,  selection  of,  81. 
Slime  on  filter  beds,  action  of,  260. 
Snow,  pollution  of  water  by,  230. 
Soft  water,  7. 

„          advantages  and  disadvantages  of,  127,  128. 
Softening  of  water,  288. 

by  addition  of  lime,  289. 

Archbutt  &  Deeley's  process,  298. 
Atkin's  process,  293. 
boiling,  288. 
distillation,  289. 
Howatson's  process,  295. 
Maignen's  process,  299. 
Porter  Clark's  process,  294. 
Stanhope's  process,  295. 
cost  of,  289,  293,  299,  302. 
purification  effected  by,  303. 
saving  effected  by,  294,  303. 
Soil,  undisturbed,  as  a  filter,  222. 

,,     influence  on  typhoid  and  cholera  organisms,  368. 
Solvent  power  of  water,  6. 
Source,  pollution  of  water  at  its,  219. 
Sources  of  supply,  13,  319. 
Specific  organisms,  diseases  due  to,  142. 
Spongilla  fluviatilis,  113. 
Spongy  iron,  271,  284. 
Spring  water,  30,  59,  69,  320. 
Springs,  59,  362. 

and  streams,  gauging  of,  100,  322, 
character  of  water  from,  69. 
how  formed,  46,  47,  61, 
law  relating  to,  449,  450. 
utilisation  of,  64. 
varieties  of,  60,  321. 
yield  of,  63,  321. 


GENERAL  INDEX 

Stand  pipes,  459. 

Standards  of  purity,  215. 

Steam  engines,  415. 

Stool  taps,  dangers  of,  148,  238. 

Storage  of  water,  361,  419. 

amount  of,  334,  358,  360,  425,  431. 
„       effect  of,  428. 
„       of  rain  water,  24,  29,  432. 
,,       pollution  of  water  during,  229,  241. 
Strata,  chief  water-bearing,  78. 
Streams,  vide  Rivers. 

Subsidence,  effect  of,  on  number  of  micro-organisms,  255. 
Subsoil,  percolation  into,  45. 
permeability  of,  45. 
pollution  of,  52,  221. 

by  gas,  228. 
saturation  of,  46. 
water  level  in,  47. 

yield  of  water  from,  50,  268,  328,  335,  352. 
Subsoil  water,  30,  45. 

law  relating  to,  452. 
movement  of,  48,  350,  352. 

,,  effect  upon  health,  225. 

towns  supplied  by,  53. 
Subterranean  rivers,  50. 

water,  cistern  theory,  76. 
river  theory,  76. 
Sulphate  of  magnesia,  337. 

Sulphuretted  hydrogen,  odour  of  water  due  to.  111. 
,,  ,,  pollution  by,  134. 

,,  water,  diarrhoea  due  to,  134. 

Sunlight,  effect  on  organisms,  250,  358. 
Supply,  dual,  341. 

,,       for  isolated  houses,  320. 

from  rainfall,  28,  329. 
Surface  water,  30,  31. 

affected  by  nature  of  soil,  34. 
chlorine  in,  34,  179. 
from  cultivated  ground,  30,  34,  360. 
from  uplands,  28,  31. 
pollution  of,  136,  219. 
supplies,  storage,  360. 
yield  of,  37,  329. 
Suspended  mineral  matters,  pollution  by,  133. 
Swamps,  bogs,  marshes,  45. 
Symptoms  of  lead  poisoning,  139,  235. 
Systematic  analysis,  need  of,  354,  355,  357. 

TABELLARIA,  114. 
Tables- 
Amount  of  water  raised  by  pumps,  398,  402. 

33 


GENERAL  INDEX 


Tables  (continued] : — 

Amount  of  nitrates  in  chalk  waters,  185. 
Analyses  of  deep-well  waters,  89,  82. 
rain  waters,  33. 

river  and  other  waters,  196,  197. 
spring  waters,  72,  73. 
subsoil  waters,  56,  57,  58. 
surface  waters,  42,  43,  44. 
Annual  water  charges,  494,  495. 
Area  of  filter  beds  and  rate  of  nitration,  266. 
Artesian  tube  wells,  yield,  etc.,  383,  384,  386. 
Bacteria  removed  by  sand  nitration,  257. 
Cholera  death-rate,  effect  of  changed  water  supply  upon,  167* 
Cost  of  boring  wells,  380,  381. 

tube  wells,  373. 

Discharge  of  water  from  pipes,  417. 

Effect  of  subsidence  on  number  of  micro-organisms,  255. 
Efficiency  of  hydraulic  rams,  408. 
Filtration,  rapidity  of,  270. 
Flow  of  water  over  notched  boards,  323. 
Force  required  to  work  pumps,  401. 
Quantity  of  water  raised  by  water  wheel,  413. 

windmill,  403. 
,,      per  stroke  of  pump,  398. 
supplied  daily  per  head  in  various  towns,  309,  312. 

,,        by  various  London  companies,  311. 
yielded  by  artesian  wells,  383,  384,  386 

tube  wells,  371,  372. 
rainfall,  18. 

„        percentage  collected  in  rivers,  97,  98. 
Water  rates,  496. 

Well  sections  around  London,  83,  84. 
Tanks  for  storage,  432. 

,,      for  rain  water,  431,  432. 
Tar  varnish,  causing  odour,  437. 
Taste  of  water,  2,  119. 
Temperature,  effect  on  water  in  exposed  reservoirs,  428. 

of  deep-well  waters,  382. 
Tow  joints,  pollution  by,  233. 
Towns  supplied  by  deep-well  water,  88,  89. 
lake  water,  36,  42,  43. 
river  water,  106. 
spring  water,  72,  73. 
subsoil  water,  54. 
surface  water,  42,  43. 
Trade  winds,  15. 

Tropical  climates,  amount  of  water  used  in,  317. 
Trunk  mains,  436. 
Tube  wells,  355,  372,  383. 

cost  of,  373. 
Turbidity  of  water,  119. 


GENERAL  INDEX  5I5 


Turbidity  of  water,  diarrhoea  due  to,  134,  135. 

Turbines,  409. 

Typhoid  bacilli,  experiments  with,  347. 

„       in  drinking  water,  206,  207,  214. 
„       influence  of  soil  on,  346,  368. 
if  „          water,  etc.,  on,  214,  250. 

„       removal  by  filtration,  256. 
fever  caused  by  water,  345,  357,  358. 
Typhoid  fever,  outbreaks  of — 

Ashton-in-Makerfield,  229. 

Bangor,  146. 

Beverley,  148,  198,  221. 

Bolan  Pass,  164. 

Buckingham,  198. 

Caius  College,  148,  238. 

Caterham,  147. 

Chester-le-Street,  152. 

Croydon,  238,  240. 

Houghton-le-Spring,  199. 

Lausen,  145. 

Maidstone,  150. 

Massachusetts,  153,  202. 

Mountain  Ash,  149,  202,  239. 

Nabburg,  147. 

Newark,  161. 

New  Herrington,  151,  354. 

Nunney,  146. 

Over  Darwen,  146 

Paisley,  229. 

Pennsylvania,  230. 

Sherborne,  148. 

Tees  Valley,  156,  201. 

Terling,  149. 

Trent  Valley,  159,  199. 

Worthing,  207. 

UNDERGROUND  sources  of  water,  47,  342,  452. 

tanks,  432. 

water,  advantages  of,  82. 
Undisturbed  soil  as  a  filter,  222. 
Unnecessary  consumption,  313. 
Upland  surface  waters,  30,  359. 

,,       surfaces,  pollution  of,  359. 
Uroglena  Americana,  113. 
Utilisation  of  springs,  64. 

VARIATION  in  daily  consumption  of  water,  317. 

,,  hourly  consumption  of  water,  310,  429. 

Varieties  of  bore  tubes,  375. 

,,          pumps,  392. 
Velocity  of  rivers,  estimation  of,  100. 


5i6  GENERAL  INDEX 

Velocity  of  water  iii  mains,  Eytelwein's  formula,  435- 

„  „        pumping  mains,  435. 

Volume  of  water  held  by  various  rocks,  48. 
Volvox  globator,  113. 

WASHINGS  from  roof,  pollution  by,  219. 
Waste  caused  by  hard  water,  127. 
of  water,  amount  of,  314. 
,,         causes  of,  313. 
„         detection  of,  313. 

prevention  of,  313,  316,  438. 
preventers,  313,  439. 
Water,  acid,  9,  362. 

boiling-point,  5. 
charges,  484,  492. 
composition  ;  properties,  etc.,  1. 
domestic  purposes,  484. 
different  sources,  13. 
meters,  484,  488,  493. 
rent  of  meter,  489,  493. 
trade  purposes,  486,  438. 
finders,  324. 

law  relating  thereto,  458. 
mains,  vide  Mains, 
rates,  459,  479,  496. 

,,     supplies  and  parish  councils,  460. 

„     Royal  Commission  Report  on,  58,  124,  158,  159,  234, 

243. 

wheels,  quantity  of  water  raised  by,  413. 
works,  classification  of,  425     . 
Watercourses,  vide  Rivers.' 
Watersheds,  330,  360. 

available  water  from,  330,  332. 
Waterworks  Clauses  Acts,  458,  460. 
Well  sections  around  London,  83,  84. 
sinkers,  364. 
sinking,  cost  of,  373. 
waters,  analyses  of,  56,  58,  88,  89. 

„       pollution  of,  53,  222,  228,  229,  364. 
,,       temperature  of,  382. 
Wells,  Abyssinian,  369. 
artesian,  74,  378. 
construction  of,  364. 
cost  of,  373. 
deep,  30,  74,  84. 

boring  and  lining,  379. 
cost  of  boring,  380. 
effect  of  pumping  on,  82,  328. 
pollution  of,  228,  229. 
yield  of,  84,  86,  327,  337,  385,  386. 
drainage  area  of,  48,  83,  224,  352. 


GENERAL  INDEX  517 


Wells,  gauging  of,  327. 
public,  468. 
shallow,  50. 

,,         drainage  area  of,  48,  224,  328. 
„         improved  construction  of,  365. 

pollution  of,  53,  222,  228. 
yield  from,  371. 
Windmills,  402. 

,,  quantity  of  water  raised  by,  403. 

Winds,  rain-bearing,  16. 

YELLOW  fever,  170. 

Yield  of  Abyssinian  tube  wells,  369. 

deep  wells,  84,  86,  337,  386. 

springs,  63,  321. 

surface  water,  37,  329. 

water  from  subsoil,  50,  268,  328,  335,  352. 
,,  various  sources,  320. 

ZINC  cisterns,  232,  234. 

„     effect  upon  health,  236. 

,,     in  water,  12. 
Zoo-parasitic  diseases,  171. 


INDEX  OF  PROPER  NAMES. 


ABBA,  347. 

Abbots  Langley,  378,  383. 

Abel,  Sir  F.,  246. 

Abergavenny,  72. 

Aberystwith,  36,  37,  38,  42. 

Abyssinia,  172. 

Adams,  Dr.,  115,  116,  240. 

Addington,  340. 

Africa,  173. 

Agra,  272. 

Aldershot,  378,  383. 

Algeria,  390. 

Alleghany,  271. 

Allen,  A.  H. ,  200. 

Alnwick,  383. 

Alps,  60. 

Altona,  168,  169,  170,  206,  257 

261,  262,  267. 

America,  175,  317,  397,  398. 
American  Desert,  390. 
Anderson,  W.,  272. 
Ansted,  15. 
Antwerp,  271,  272. 
Archbutt  and  Deeley,  298,  299. 
Argentina,  390. 
Argentine  Republic,  17. 
Aristotle,  1. 
Armstrong,  Dr.,  310. 
Artois,  75. 
Ashby,  481,  482. 
Ashley,  H.,  396. 
Ashton-in-Makerfield,  229. 
Ashton-under  Lyne,  496. 
Assam,  17. 
Aston,  384. 
Atherstone,  72,  309. 
Athol,  270. 
Atkins,  269,  270,  293. 
Atlanta,  270,  271. 
Attfield,  D.  H.,  251. 
Attfield,  J.,  61,  293. 


260, 


Australia,  17,  174. 
Axe  Edge,  91. 

BABES,  145. 

Bahia,  173. 

Ball,  A.  J.  A.,  52. 

Ballard,  146. 

Bangor,  146. 

Barcaldine,  386. 

Bardfield,  J.  H.,  479. 

Barking,  84,  309. 

Barnard  Castle,  157,  201,  202. 

Barnes,  256. 

Barnstaple,  43. 

Barrow-in-Furness,  496. 

Barry,  Dr.,  94,  140,  156,  157,  158, 

159,  199. 

Bateman,  17,  333,  422. 
Bath,  63,  184,  496. 
Batley,  43. 
Battersea,  166. 
Baynes,  198. 
Beardmore,  99,  100, 102. 
Beccles,  372. 
Bechuanaland,  389. 
Bedford,  309. 
Berlin,  48,  52,  53, 114,  228,  261,  312, 

341,  348. 
Berwick,  309. 
Bettington,  143. 
Beverley,  148,  198,  221. 
Bhagsoo,  138. 
Bindon  Hills,  480. 
Birkenhead,  88,  496. 
Birmingham,  312,  496. 
Bishop  Stortford,  57. 
Blackall,  386. 
Blackburn,  496. 
Black  wall,  246. 
Blackwell,  103. 
Blaxall,  Dr.,  148. 


(519) 


520 


INDEX  OF  PROPER  NAMES 


Bolan  Pass,  164. 

Bolton,  116,  496. 

Bombay,  817. 

Bona,  144. 

Boston,  43, 113, 114, 154,192,203,312. 

Boudin,  144. 

Boulnois,  316. 

Boulogne,  272. 

Boultbee,  387,  388. 

Bourn,  84,  384. 

Bozel,  138. 

Bracebridge,  135. 

Bradford,  140,  266,  312,  316,  438, 

454,  497. 

Braintree,  185,  494,  495. 
Brazil,  174. 
Brentford,  122. 
Bridlington,  309. 
Brightlingsea,  494,  495. 
Brighton,  89,  339,  396,  496. 
Bristol,  64,  72,  309. 
Bristown,  389. 
British  Islands,  16,  18. 
Brodie,  Sir  B.,  92. 
Brown,  Dr.,  189. 
Brunner,  Dr.,  245. 
Brussels,  341. 

Buchanan,  Dr.,  148,  149,  238,  240. 
Buchanan,  Sir  G.,  195. 
Buchner,  Prof.,  250. 
Buckingham,  198. 
Buda-Pesth,  48,  53,  225. 
Buenos  Ayres  and  Rosario  Railway 

Company,  390. 
Bulnois,  316. 

Burnham,  57,  372,  494,  495. 
Burnley,  496. 
Burnmoor,  11. 

Burton,  372,  378,  418,  425,  430. 
Bury,  496. 
Bushmanland,  389. 
Buxton,  2,  42,  63,  184,  477. 

CALCUTTA,  273,  317. 
California,  389. 
Calkins,  G.  N.,  112. 
Calverley,  235. 
Cambre,  341. 
Cambridge,  148,  238. 
Camden,  294. 
Canterbury,  89,  301. 


Cape  of  Good  Hope,  172,  388. 

Cape  Town,  273. 

Cardiff,  383,  497. 

Carlisle,  106,  266,  497. 

Carnforth,  42. 

Carter,  Vandyke,  145. 

Castle  Donington,  89. 

Caterham,  61,  147,  301. 

Cavendish,  1. 

Chadwell  Springs,  83. 

Chaldon,  479. 

Charlestown,  167. 

Charleville,  386. 

Chatham,  89,  185,  384. 

Chaux  de  Fonds,  412. 

Chelmsford,  68,  309,  372,  494,  495. 

Chelsea,  266,  311. 

Cheltenham,  63,  73,  106,  107,  108, 

114,  116,  117,  497. 
Chepstow,  72,  309. 
Cherraponjee,  17. 
Chertsey,  245. 
Cheshunt,  83. 
Chester,  497. 
Chester-le-Street,  152. 
Chewton  Mendip,  64. 
Chicago,  122. 
Chichester,  346. 
Chicopee,  156,  203. 
Chili,  222. 
China,  17,  74. 
Church  Coppenhall,  474. 
Cirencester,  383. 
Clacton-on-Sea,  490,  494,  495. 
Clark,  289,  290,  298,  301,  304. 
Clark,  Prof.,  127. 
Clifton,  63. 
Clitheroe,  276. 
Clown,  56. 

Colchester,  89,  185,  486,  494,  495. 
Cold  Norton,  89. 
Colesburg,  389. 
Collins,  E.,  314. 
Colne  Valley,  290,  384. 
Connecticut,  113. 
Cooke,  115. 
Cornwall,  32. 
Coventry,  88. 
Cressbrook,  477. 

Crookshank,  Prof.,  207,  208,  211. 
Crossley,  Otto,  483. 


INDEX  OF  PROPER  NAMES 


Crowden,  422. 

Croydon,  226,  238,  240,    336,    339, 

453,  454. 

Cumberland,  16,  32,  125. 
Cunnamulla,  386. 

DAGENHAM,  372. 

Dalton,  Dr.,  49. 

Damflask,  423. 

Danbury,  73. 

Darlington,  106,  156,  157,  200,  201, 

202,  497. 
Dauben  See,  60. 
D'Aubuisson,  102. 
Davenport,  474. 
Dawkins,  Prof.  Boyd,  87,  421. 
Day,  Justice,  467. 
Deacon,  314,  439. 
Delepine,  Prof.  S.,  210,  213. 
Demerara,  273. 
Denny,  468. 

Denton,  E.  B.,  28,  281,  431. 
Derby,  41,  497. 
Derbyshire,  33,  91,  138. 
De  Ranee,  17. 
Deseret,  389. 
Devon,  16,  32. 
Dewsbury,  42,  497. 
Dibdin,  246,  349. 
Dickenson,  49. 
Doncaster,  106,  497. 
Dorchester,  479. 
Dorset,  148. 
Ducat,  349. 
Dudley,  497. 
Dumfries,  265,  266. 
Duncanson,  T.,  311,  440. 
Dupre,  Dr.,  202,  246. 
Durham,  106,  151,  152,  354. 

East  Ham,  309. 

East  London  Water  Company,  266, 

311,  396,  485,  486,  494,  495. 
East  Stratton,  372. 
Eaton,  16. 
Eaton  Hall,  384. 
Eberth,  208,  209. 
Edinburgh,  39,  229,  255. 
Edingley,  161. 
Edwards,  Dr.,  155,  249. 
Egypt,  172,  174. 


Elbourne,  57. 

Ely,  106. 

Emnierick,  Dr.,  245. 

Escher,  412. 

Essex,  11,  82,  83,  111,  118,  124, 
143,  149,  167,  181,  182,  185, 
203,  216,  324,  336,  380,  388, 
485. 

Eston,  157. 

Eton  College,  175. 

Evans,  Sir  J.,  76,  78. 

Evesham,  56. 

Exeter,  316,  497. 

Eytelwein,  102,  436. 

FARLOW,  Dr.,  117. 

Fedschenko,  173. 

Fisher,  W.  W.,  198. 

Fliigge,  216. 

Fodor,  48,  225. 

Forschammer,  192. 

Foster,  Lott  &  Co.,  479,  480. 

Fraenkel,  C.,  52,  348. 

France,  60,  75. 

Frankland,  Prof.,  121,  176,  192, 
193,  200,  201,  205,  209,  222, 
230,  245,  246,  251,  253,  255, 
267,  284,  303. 

Friihling,  327. 

Fuertes,  327. 

GAINSBOROUGH,  160. 

Garrett,  Dr.,  11,  114,  116,  117. 

Gateshead,  497. 

Gemmi,  60. 

Geneva,  410. 

Geradin,  246. 

Germany,  174,  429. 

Gibraltar,  170. 

Gilbert,  49. 

Glamorgan,  149. 

Glasgow,  36,  39,  40,  42,  124,  167, 

234,  235,  253,  312. 
Glenfield  Co.,  396. 
Glengyle,  40. 
Gloucester,  117. 
Gobi,  17. 
Gooch,  Dr.,  175. 
Gorges  de  1'Areuse,  412. 
Gosport,  384. 
Grand  Junction  Co.,  266,  311. 


522 


INDEX  OF  PROPER  NAMES 


Grantham,  72,  309. 
Gravesend,  372. 
Great  Baddow,  483. 
Great  Britain,  345,  364. 
Greenwich,  18. 
Grenelle,  75. 
Griiber,  Max,  216. 
Giistrow,  248,  249. 

HALIFAX,  43,  497. 

Hall,  136. 

Halsbury,  Lord,  455. 

Halstead,  89,  309,  494,  495. 

Hamburg,  153, 168,  169,  206,  262. 

Hamilton,  167. 

Hampshire,  138,  422. 

Hampton,  245,  256. 

Hampton  Court,  93. 

Hanley,  88. 

Hanover,  389. 

Harrison,  Dr.,  135. 

Hart,  E.,  345. 

Harvard  University,  117. 

Harwich,  81,  89. 

Hassall,  122. 

Hastings,  78. 

Hauser,  Dr.,  346. 

Havant,  384. 

Hawksley,  316,  333,  334. 

Haynes,  Surg.-Capt. ,  164. 

Heaton,  Dr.,  237. 

Heckmondwike,  42. 

Hemel  Hempstead,  49. 

Hendon,  175. 

Henley-on-Thames,  269,  293. 

Hennel,  267. 

Hereford,  372. 

Hertford,  378,  383. 

Hertfordshire  Bourne,  60. 

Herts  and  Essex  Co.,  494,  495. 

Heybridge,  89. 

Heywood,  308. 

Hicks,  Dr.,  175. 

Hirsch,  173. 

Hodson,  81,  82. 

Hoe  Lane,  83. 

Holland,  Dr.,  127. 

Holmfirth,  466. 

Hornsey,  238. 

Houghton-le-Spring,  199. 

Houston,  213,  214,  229, 


Huddersfield,  309,  497. 

Hughes,  102. 

Hull,  497. 

Humber,  333. 

Hunter,  Lovell,  139,  140,  235. 

ICELAND,  174. 

Ilford,  372. 

India,  138,  167,  173,  222,  225. 

Ingatestone,  57,  271. 

Iowa,  176. 

Ireland,  345. 

Isle  of  Wight,  81. 

Isler  &  Co.,  84,  371,  381,  385. 

Italy,  174. 

JANEIRO,  173. 
Japan,  172. 
Jessel,  450. 
Johns  Bros.,  479. 
Johnston,  Dr.,  281. 

KALAHARI,  17. 

Kamaon,  138. 

Karoo,  388. 

Katrine,  Loch,  36,  39,  234,  235,  253. 

Keighley,  11,  276,  497. 

Kelly,  Dr.,  239. 

Kempster,  B.,  368. 

Kennet  and  Avon  Canal,  103. 

Kent,  81,  304. 

Kent  Co.,  311,  339. 

Kentish  Town,  81. 

Kern  County,  389. 

Kew,  18,  166. 

Key  wood,  H.  G.,  68,  476. 

Khasia  Hills,  17. 

Kilmarnock,  396. 

Kingsdown,  Lord,  451. 

Kingsheath,  383. 

King's  Langley,  49. 

King's  Lynn,  65,  73. 

Kirkheaton,  157. 

Klein,  Prof.,  137,  213. 

Knaith,  199. 

Knaresborough,  106. 

Koch,  52,  53,  55,  153,  168, 170,  207, 
210,  214,  215,  221,  223,  257, 
260,  261,  262,  347,  367. 

Kiimmel,  248. 

Kutzing,  115. 


INDEX  OF  PROPER  NAMES 


523 


LAMBERT,  479. 

Lambeth,  293. 

Lambeth  Co.,  266,  311. 

Lancashire,  9,  33,  146. 

Lancaster,  497. 

Latham,  B.,  76,  77,  226. 

Latham,  P.  M.,  136. 

Lausen,  145. 

Laveran,  143,  145. 

Lawes,  49. 

Lawrence,  153,  154,  155,  156,  249. 

Leamington,  88,  106. 

Lechlade,  372,  478. 

Leeds,  42,  106,  264,  266,  496. 

Le  Grand  and  Sutcliffe,  371,  372, 
381,  382. 

Leicester,  41,  266,  496. 

Leipzic,  341. 

Leuckart,  174. 

Lindley,  457. 

Lincoln,  135,  372. 

Lincolnshire,  84,  85,  143,  159. 

Liverpool,  36,  43,  80,  83,  253,  294, 
311,  312,  315,  317,  382,  429, 437, 
496. 

Llanelly,  237. 

Llyn  Llygad  Rheidol,  Lake,  36,  37. 

London,  81,  83,  84,  93,  124,  136, 
161,  163,  165,  166,  185,  186, 
214,  238,  244,  249,  252,  255, 
257,  262,  264,  265,  267,  308, 
311,  312,  316,  340,  433. 

London  and  N.W.  Railway  Com- 
pany, 294. 

London  Orphan  Asylum,  384. 

Long  Branch,  270. 

Long  Eaton,  89,  384. 

Low,  Dr.  Bruce,  159,  160,  199. 

Lowell,  153,  154,  155, 156,  202,  249. 

Lustig,  212. 

Lynn,  66,  67,  68. 

MACCLESFIELD,  496. 

Mace,  211. 

Macnaughten,  Lord,  455. 

Madras,  143,  317. 

Madrid,  346. 

Maidstone,  150,  240. 

Maiden,  54. 

Maldon,  68,  89,  475,  489,  494,  495. 

Malham  Cove,  60, 


Manchester,  36,  42,  49,  167,  234, 
235,  312,  421,  438,  496. 

Manson,  172. 

Marseilles,  144,  145. 

Martin,  Baron,  450. 

Martin,  S.,  346. 

Massachusetts,  18,  34,  35,  36,  43, 
53,  57,  68,  96,  98,  111,  112, 113, 
114,  153,  180,  189,  191,  202, 
243,  249,  256,  262,  264,  270, 
427. 

Mather  &  Platt,  383. 

Matlock,  63. 

M'Clellan,  Dr.,  138. 

McWeeney,  Dr.,  347. 

Meade-Bolton,  212. 

Mecklenburg,  248. 

Melbourne,  89. 

Melrose,  72,  309. 

Melton,  136,  228. 

Melton  Mowbray,  372. 

Melville  Island,  5. 

Meriden,  113. 

Merryweather,  437. 

Merthyr  Tydfil,  43. 

Metz,  136. 

Mexico,  134. 

Michigan,  175. 

Middlesborough,  106,  156, 157,  158, 
200,  308,  337,  496. 

Middleton,  113. 

Miers  and  Crosskey,  46. 

Miguel,  23. 

Migula,  211,  212. 

Millbank  Prison,  136. 

Miller,  Prof.  W.A.,  234. 

Mills,  H.  F.,  153. 

Millwall,  372. 

Milwaukee,  317. 

Miquel,  211. 

Mistley,  89,  185. 

Molesworth,  401. 

Monte  Video,  272. 

Moore,  Surg.-Maj.  R.  R.  H.,  144. 

Morningside,  229. 

Mountain  Ash,  149,  202,  239. 

Muckadilla,  386. 

Munich,  48,  225,  245,  251. 

Munro,  Dr.,  229. 

Murphy,  Dr.  Shirley,  161. 

Musselburgh,  372, 


524 


INDEX  OF  PROPER  NAMES 


NABBURG,  147. 

Nantiago  Lead  Mine,  37. 

Nantwich,  474. 

Natal,  17. 

Newark,  106,  161,  162. 

New  Brompton,  73. 

Newburyport,  155,  156,  249. 

Newcastle,  152,  310. 

New  Herrington,  151,  223,  354. 

New  River  Co.,  255,  265,  266,  311. 

New  Ross,  372. 

New  South  Wales,  387. 

Newton,  53,  57. 

New  York,  135,  312. 

Norfolk,'  185. 

Normanby,  157. 

North,  144. 

North  America,  34,  387. 

Northampton,  497. 

Northumberland,  33. 

Norwich,  56,  81,  89,  185,  316. 

Norwood,  113. 

Nottingham,  41,  309,  496. 

Nottinghamshire,  138, 159. 

Nunney,  146. 

OAKLAND,  270. 
Odling,  Dr.,  246. 
Ogden,  421. 
Okehampton,  43. 
Oldham,  497. 
Orizaba,  134. 
Orlandi,  347. 
Ormesby,  157. 
Ottumwa,  270. 
Oude,  138. 
Oudshoorn,  277. 
Oven  Darwen,  146. 
Oxford,  245. 

PAGE,  Dr.,  148,  151,  198,  199. 
Paisley,  167,  229. 
Palmberg  and  Newsholme,  341. 
Paris,  23,  92, 174,  247,  341,  384,  410. 
Parkes,  Dr.,  143,  145,  228,  286,  287, 

306,  323. 
Parry,  J.,  429. 
Parsons,  Dr.,  198. 
Patricroft,  383. 
Pattinson  &  Stead,  200. 
Pennine  Chain,  17, 


Pennsylvania,  230. 

Peru,  222. 

Pettenkofer,  Prof.,  48,  225,  346. 

Philadelphia,  312. 

Pittsburg,  270. 

Pittville  Park,  115. 

Plymouth,  42,  106,  113,  497. 

Plynlimmon,  36,  37. 

Pole,  Dr.,  332,  333,  334. 

Poncelet  &  Lesbros,  104. 

Pontefract,  88. 

Poole,  56. 

Poonah,  168. 

Porter-Clark  Co.,  294. 

Portsmouth,  228. 

Power,  W.  H.,  10. 

Prague,  136. 

Preston,  42,  497. 

Prestwich,  47. 

Procacci,  Dr.,  250. 

Pudsey,  139,  235. 

Purfleet,  246,  372. 

Purleigh,  489. 

Putney,  234. 

QUEENSLAND,  382,  385. 

RAFTER,  113. 

Rainham,  372. 

Rankine,  Prof.,  306. 

Rawlinson,  Sir  R.,  373,  380,  416, 

420,  437. 
Rawtenstall,  57. 
Reading,  16,  245,  274,  275,  481. 
Redhill,  147. 
Remsen,  Prof.,  113. 
Revere,  54,  57. 
Richard  Freres,  21. 
Richardson,  Sir  B.  Ward,  126. 
Richmond,  339. 
Rideal,  Dr.,  287. 
Rigby,  457. 
Ripon,  106. 
Rivers — 

Afon  Gaseg,  146,  147. 

Aire,  60. 

Calder,  106,  273. 

Chelt,  107. 

Chicopee,  156,  203. 

Danube,  53. 

Don,  106. 


INDEX  OF  PROPER  NAMES 


525 


Rivers  (continiLed) : — 
Eden,  106. 

Elbe,  168,  169,  170,  206. 
Etherow,  421. 
Exe,  33. 
Hamps,  60. 
Harre,  341. 
Hooghly,  273. 
Irwell,  243. 
Isar,  48,  245. 
Itchen,  422. 
Kennet,  243,  274,  275. 
Lea,  83,  86,  93,  94,  106,  108, 

163,  249,  251,  252,  267. 
Learn,  106. 
Loddon,  99. 
Loiret,  60. 
Loxley,  423. 
Manifold,  60. 
Medway,  99. 
Merrimac,  111,  154,  155,  156, 

202,  249,  263. 
Mersey,  33,  243. 
Mew,  106. 
Mimram,  99. 
Mohawk,  135. 
Mootla,  168. 
Nene,  99. 
Nidd,  106. 
Ouse,  106,  198. 
Pleisse,  341. 
Potomac,  271. 
Schwarza,  341. 
Seine,  93,  247. 

Severn,  99,  106,  107,  108,  117. 
Sorgue,  60. 
Spree,  48,  341. 
Sudbury,  96,  97,  98. 
Tees,  33,  94,  106, 155,  156, 157, 

158,    159,    199,  200,    201, 

206,  208. 
Test,  422. 
Thames,  16,  51,  86,  92,  93,  94, 

98,  99,  106,  107,  108,  122, 

124, 125,  163, 166,  243,  245, 

246,  249,  251,  252,  256,  257, 

267,  288. 

Trent,  159,  160,  161,  199. 
Ure,  106. 
Vannes,  341. 
Wandle,  99,  453,  454. 


Rivers  (continued) : — 

Warnow,  248  (see  p.  527). 

Wash,  65. 

Washburn,  106,  264. 

Wear,  106. 

Wharfe,  106. 

Witham,  135. 

Wye,  477. 

Yare,  106. 
Rivington,  421. 
Roberts,  26. 

Robertson,  Dr.,  346,  347. 
Rochdale,  497. 
Rochdale  Canal,  17. 
Rochester,  385. 
Rome,  144. 
Romsey,  422. 
Rondelli,  347. 
Roques,  232. 
Roscoe,  Prof.,  5. 
Rostock,  248. 
Rothamstead,  49. 
Rotherhithe,  372. 
Rotterdam,  114. 
Roux,  G.,  212. 
Rugby,  294,  337. 
Russia,  168,  176. 

SAFFRON  WALDEN,  56,  89, 185,  309, 

494,  495. 
Sahara,  17,  390. 
Salford,  134,  167. 
Sandown,  106. 
Sandgate,  421. 
San  Joaquin  Valley,  389. 
San  Louis  Valley,  389. 
Scarborough,  497. 
Scatterty,  Dr.,  11,  276. 
Schenectady,  135. 
Scotch  Highlands,  125. 
Scott,  17. 
Sedgley  Park,  135. 
Sedgwick,  Dr.,  155. 
Sedgwick,  Prof.  W.  F.,  114. 
Sheffield,  9,  41,  333,  421,  423,  497. 
Sherborne,  148. 
Shields,  16. 
Shiplake,  243. 
Shoeburyness,  494.  495. 
Shoreditch,  314,  316. 
Shrewsbury,  106. 


INDEX  OF  PROPER  NAMES 


Silcock,  67,  68. 

Slagg,  104. 

Sleaford,  384. 

Slough,  384. 

Smith,  Angus,  23,  233,  321,  478. 

Smith,  I.  C.,  68. 

Smith,  Prof.  W.  E.,  247. 

Snow,  Dr.,  165. 

Snowdon,  19. 

Soignes,  341. 

Somersetshire,  146. 

Somerville,  15. 

Sonning,  481. 

Sonsino,  Dr.,  172,  173. 

Southampton,   57,    167,   293,   339, 

383,  384. 

South  Australia,  386. 
Southend,  84,  89,  185,  494,  495. 
South  Essex  Co.,  494,  495. 
Southminster,  73,  490. 
Southmoor,  152. 
Southport,  88,  497. 
South  Stockton,  156. 
South wark  and  Vauxhall  Co.,  234, 

266,  311. 

Sowerby  Bridge,  17. 
Soyer,  127. 
Spalding,  84. 
Spear,  J.,  202,  239. 
Spence,  271,  273. 
Springfield,  73,  483. 
Staffordshire,  33,  60. 
St.  Albans,  378,  383. 
Staleybridge,  43. 
Stampfel,  230. 
Stanstead,  494,  495. 
St.  Austell,  72,  309. 
St.  Bon,  138. 
Steeple,  89. 
Stephenson,  382. 
Stevens,  Dr.,  146. 
St.  Gothard,  174. 
St.  Helens,  312,  347,  497. 
St.  Maur,  410. 
Stock,  F.  K.,  200,  201. 
Stockholm,  341. 
Stockport,  383. 

Stockton,  106, 156,  157,  158,  201. 
Stoddart,  F.  W.,  186,  187. 
Stoke  Newington,  255. 
Stratford,  185. 


Streatham  Common,  84. 

Stroud,  43,  56,  73,  298. 

Stye  Pass,  17. 

Styrian  Alps,  341. 

Sudbury,  89. 

Suffolk  Asylum,  136,  203,  378. 

Surrey,  81,  147. 

Sussex,  138. 

Sutcliff,  B.,  375. 

Swansea,  72,  309,  312,  372,  497. 

Swindon,  340. 

Switzerland,  145,  146,  174. 

Symons,  15,  21,  37. 

Syracuse,  115. 

Syria,  171. 

TASMANIA,  136. 

Taylor,  J.,  Sons  &   Santo  Crimp, 

289. 

Teddington,  93. 
Tegeler,  Lake,  114,  341. 
Tendring,  494,  495. 
Tenterden,  Lord,  449. 
Terling,  149. 

Tewkesbury,  106,  107,  108. 
Thanet,  78. 
Theydon  Bois,  167. 
Thirlmere,  36. 
Thorne,  Dr.,  147,  157,  200. 
Tidy,  Dr.,  192,  193,  199,  201,  245. 
Torksey,  199. 
Totnes,  72.' 
Towyn,  42. 
Tring,  301. 
Troy,  143. 

Tunbridge  Wells,  384. 
Turin,  347. 
Turner,  Dr.  G.,  136,  137,  203,  378, 

379. 
Tyndall,  Prof.,  110,  122. 

UNITED  STATES,  248,  270,  312,  389. 
Uruguay,  390. 
Utah  Territory,  389. 
Uxbridge,  384. 

VADAKENCOULAM,  168. 
Vaughan,  175. 
Vaughan- Williams,  457. 
Venables,  Dr.,  237. 


INDEX  OF  PROPER  NAMES 


527 


Veuterstad,  389. 
Victoria,  386. 
Victoria,  West,  389. 
Vienna,  125,  216,  341. 
Vries,  Prof.  Hugo  de,  114. 
Vyrnwy,  Lake,  36,  253. 

WAKEFIELD,  106,  266,  273,  497. 

Walden,  57. 

Wales,  16,  32,  33,  146. 

Wales,  Dr.  P.  S.,  270,  271. 

Walker,  274,  275. 

Wallingford,  383. 

Waltham,  53,  57. 

Waltham  Abbey,  83. 

Waltham  Cross,  84. 

Walthamstow,  83,  309. 

Wandsbeck,  168,  169. 

Wandsworth,  234. 

Wanklyn,  Prof.,  191. 

Ware,  57. 

Warrego,  386. 

Warrington,  383. 

Warrington,  Dr.,  222. 

Washington,  270,  389. 

Watford,  378,  383. 

Watson,  Baron,  450. 

Webster,  J.  &  J.,  477. 

Weld,  480. 

West  Indies,  174. 

West  Lulworth,  412,  479,  480. 

West  Middlesex   New  Eiver   Co. 

255,  256,  266,  311. 
Westminster,  165. 
Westmoreland,  16,  32. 
Weston-Super-Mare,  72,  309. 
West  Biding  of  Yorkshire,  8. 
West  Worthing,  239,  383. 
Weymouth,  167. 


Wheatley,  Dr.,  229. 

Whitaker,  W.,  65,  67,  76,  337,  420. 

White,  Dr.  Sinclair,  9. 

Wickham  Bishops,  337. 

Widford,  372. 

Wigan,  43. 

Wightman,  Mr.  Justice,  453. 

Wildbad,  184. 

Willesden,  294. 

Wills,  Chas.,  162. 

Wilson,  A.  C.,  158,  201. 

Wilson,  Maclean,  Dr.,  138,  152. 

Wiltshire,  81. 

Wimbledon,  185. 

Wimborne,  383. 

Windsor,  245. 

Winfrith,  479,  481. 

Winogradsky,  222. 

Witham,  185,  372. 

Wolverhampton,  88,  309,  310,  497. 

Woodhall  Spa,  340. 

Woodhead,  Dr.  Sims,  281. 

Woodhead  Reservoir,  422. 

Wooldale,  466. 

Woolwich,  384. 

Worcester,  106,  107,  108. 

Worthing,  56,  89,  206,  207,  255. 

Wraysbury,  372. 

Wright,  Justice,  467. 

Writtle,  55,  57,  181. 

Wynaad,  144. 

YARROW,  421. 

Yeovil,  73,  309. 

York,  106. 

Yorkshire,  33,  60,  139,  148,  176. 

Yorkshire,  West  Riding,  8,  140. 

ZURICH,  412. 


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